I’ve noted the most common issues you’d face with your Rheem gas, electric, and tankless water heater from my experience. The main problems I’ll discuss in this ultimate Rheem water heater troubleshooting guide are:

• No hot water
• Not enough hot water
• Condensation
• The pilot won’t light
• The main burner won’t light
• And more

I’ll not only explain the problems but also discuss how you can solve each of these issues in detail. So, let’s dive right in.

Rheem Water Heater Troubleshooting [Gas Units – Ultimate Guide]

No matter which type of Rheem gas water you use, the problems will be similar. It doesn’t matter much if you have a power vent heater, performance platinum heater, or classic heater. The issues I’ll discuss are universal and applicable to all of them.

There would be some variations if you own a Rheem Professional Prestige Maximus Gas unit. That’s why I have a dedicated section on it that you can check later on. For now, let’s look at the common problems that you’d face with your Rheem gas heater.

01. No Hot Water

Your heater has one job – to provide hot water in your time of need. And when it fails to do just that, it’s obvious that you’ll be frustrated. It’s a common issue that you could also face with your gas water heater.

The main reasons behind not getting any hot water from your Rheem gas water heater are:

• There is no gas supply.
• The power switch is turned off.
• The combustion shut-off device was tripped.
• The gas control shut-off device was tripped.
• Faulty thermostatic mixing valve

How To Fix:

First things first, you have to make sure that the heater is on. Even if you didn’t do it, somebody else in your home could have done it. So, press the “On/Off” button again to turn on the heater if it is switched off.

Next, you have to check for gas supply issues. If the manual gas shut-off valve isn’t open all the way, it could lead to gas supply issues. So, check that and make sure it’s turned all the way to the On position.

The valve should be completely parallel to the gas lines. If you use the wrong type of gas for your heater, that could also cause gas supply issues. Make sure you’re using natural gas if your heater needs natural gas. You can’t convert your heater from running on natural gas to LP gas.

If you didn’t pay your utility bills recently, the gas supply may have been cut off. Try to operate another gas-powered appliance and check if it works. If it does, that means there is no issue with the gas supply.

The combustion shut-off and gas control shut-off devices are both safety mechanisms to prevent accidents. They shut off the gas supply to the water heater whenever there are unwanted risks. As this is a serious matter, you should consult a qualified technician to help you with this one.

Finally, you need to check whether you have a bad thermostatic mixing valve. Test the temperature of water at all the hot water faucets. If the no hot water issue only occurs at one faucet, the mixing valve in that valve has gone bad and is stuck closed. You’ll have to replace it to get hot water.

So, there are many reasons why a gas water heater may not turn on or not heat the hot water. Luckily, I also have a dedicated guide on this topic if you haven’t found the solution yet. Visit my guide on Rheem water heater isn’t heating to find more causes and solutions to this problem.

02. Not Enough Hot Water

There’s another issue that’s almost as annoying as getting no hot water. That issue is getting inadequate hot water. It means the water you get at the hot water faucet is lukewarm but it’s nowhere near the temperature you desired.

The primary reasons behind getting inadequate hot water from your heater are:

• Setting the thermostat too low.
• Too much hot water usage.
• Low gas pressure.
• Open or leaking hot water faucets.
• Colder water supply.
• Melted or damaged dip tube.

How To Fix:

As obvious as it may seem to set the right temperature, many people still make this mistake and set their thermostats at a low temperature. So, check your thermostat and turn it up if you’ve made that common mistake as well.

The issue with gas water heater thermostats is that they don’t state the temperature. Instead, they have positions where you can adjust the gas control knob. So, here’s a quick guide about the gas control knob positions and their corresponding temperatures:

• Low – 90° F
• Low To Hot – Between 90° F and 120°F (7-8°F increments at each point)
• Hot – 120°F
• A– 130°F, B – 140°F, C – 150°F
• Very Hot – 160°F

Hopefully, you’ll have no issues setting the right temperature from here on. Take a screenshot of this temperature setting guide so you can always return to it in case you forget the settings.

Next, you have to make sure that your hot water usage isn’t beyond the capacity of your heater. You should already know the capacity of your heater – it could be 40 gallons, 50 gallons, or more.

If the demand for hot water exceeds that, your heater won’t be able to keep up with that and you’ll get lukewarm water. You can check if this is the issue by seeing if multiple hot water faucets are being used at the same time.

If you have a large family and there’s an overlap when it comes to hot water usage, it could explain why you’re facing this issue.

Your first option is to plan a bathroom schedule so that there’s not a huge demand for hot water at any given moment. Otherwise, you can upgrade to a bigger heater to fix this issue.

The maximum inlet gas pressure for Rheem gas heaters in cases of both natural gas and LP is 14” WC. However, the minimum gas pressure varies depending on your heater. Check the rating plate of your water heater to know the exact value of the pressure for your heater.

You have to check the inlet pressure and compare it with the value given in the rating plate. If they’re matching, then there are no issues with the gas pressure. But if you don’t have the correct gas pressure, it’ll have to be adjusted to get hot water properly again.

Then, you should check for leaks. Even a minor leak on the hot water side can reduce the temperature of the hot water by a large degree. If you can identify any leak, you’ll have to seal it and replace the worn-out components.

The cold water itself can be colder due to the freezing weather conditions. In that case, it’s normal to get cooler water from the heater. You can turn up the temperature even higher to get hot water again.

Finally, you have to consider the possibility that the dip tube has melted. Cold water goes to the bottom of the tank as it’s directed by the dip tube. That water gets heated directly by the main burner. In the meantime, the water goes from the top of the tank to hot water faucets if there’s demand for it.

When the dip tube is damaged, the cold water gets mixed with the hot water. So, the overall water temperature gets reduced and you get less hot water. If that’s the case with your heater, you’d have to replace the dip tube. Don’t worry, I’ll show you exactly how you can do it.

How To Replace Rheem Water Heater Dip Tube?

Dip tubes come in different shapes and sizes. It’s important that you get the right replacement part if the dip tube in your water heater is damaged. Visit this Rheem dip tube sizing guide to find the right part for your heater.

You’ll need a few additional tools to replace the dip tube. A flathead screwdriver, an adjustable wrench, a pipe wrench, and a garden hose will come in handy in this replacement job. Once you get your hands on them, you can follow these steps to replace the dip tube:

1. Turn off the gas supply to the water heater and unplug it from its power source. Then, turn off the cold water supply to the water heater as well.
2. Attach the garden hose to one end of the drain valve and place the other end near a floor drain. Open the drain plug to start getting rid of water inside the tank. You only need to drain around 9-10 gallons of water when replacing the dip tube.
3. Disconnect the cold water supply line to your water heater. The tools you’ll need to do that depend on your water heater. You can remove the cold water supply line with an adjustable wrench if there is a flex connector. But if your heater has copper tubing, your only option is to cut it.
4. Take off the plastic shroud to access the dip tube from the top of your water heater. Then, rotate the dip tube using the adjustable pliers or a pipe wrench. When the dip tube becomes loose, you can pull it out.
5. Cut the new dip tube to match the length of the old one. Apply some Teflon tape to the water heater and then, put it in. Tighten the dip tube, reattach the plastic shroud, and reconnect the cold water supply line.

That’s all it takes to replace the dip tube. It can seem complicated if you don’t know what you’re doing. If you need more detailed instructions, check out my post on replacing dip tubes in Rheem water heaters for more information.

It does take some expertise and previous experience working on heaters to replace the dip tube. So, it wouldn’t be a good starting project if you’ve never made repairs on your water heater before. If that’s the case with you, I recommend going for a qualified technician to do this job.

03. Condensation

When you install a new heater and you see condensation forming on the tank, it’s normal to be worried. But don’t worry, condensation is a normal part of the operation in new heaters.

It’s also normal for the burner to make a sizzling sound as droplets of water fall on it. But the condensation should disappear after a while. You only need to be alarmed when you’ve used your heater for a decent period and the condensation won’t go away or reappear.

The moisture from the products of combustion creates condensation. But it’s not good for the main burner in the long run. When there’s too much condensation, the main outage can be damaged. The most likely culprit here is fitting the pipes loosely.

Finally, using an undersized heater compared to your needs can also create condensation. The burner can get damaged after a while if you don’t do something to fix this issue soon.

How To Fix:

If the condensation issue remains even after you have waited for a while on a new installation, the pipe fitting could be loose. There must be a small leak that has allowed the condensation to happen.

You have to rectify this poor installation job. Talk to the people who installed the heater and have them check it out. Once the pipe fitting is tight, the condensation should go away.

Finally, make sure you have the right water for your needs. You can upgrade to a bigger heater or limit the hot water usage at a time. Pick the option that’s more feasible for you. But you can’t leave this issue hanging as you don’t want to cause damage to the main burner of your heater.

04. Yellow Flame

You should have a nice blue flame when the heater operates normally. But when you see a yellow flame instead, it’s normal to be alarmed.

The main reason behind getting yellow flame is scale build-up on the main burner. The debris on the burner interferes with the combustion process. The end result is a yellow flame.

Apart from the burner being clogged, restrictions on the flue or air inlet openings can also cause this issue. Finally, the lack of sufficient combustion or ventilation air can also cause a yellow flame.

How To Fix:

First, you have to check the burner and inspect if it’s dirty. You’ll have to pull it out to check it. The process is easy. You can follow these steps to do it:

1. Shut off the gas supply to the heater and wait for it to cool down.
2. Remove the connections of the water heater at the gas valve. It includes the thermocouple, the gas supply to the main burner, and so on.
3. Once you’ve removed the connections, unscrew the four screws holding the burner access door in place.
4. Remove the access door.
5. Pull out the main burner assembly gently to make sure you don’t damage anything.

If you don’t feel comfortable doing it yourself, you can always delegate it to a qualified technician. Once you’ve pulled out the burner, inspect its condition. You’ll have to clean it if it’s dirty.

You can use a vacuum cleaner to get the visible dirt out of the burner. Then, you can scrub it with a mild detergent until you get most of the dirt out of it. If the burner is too dirty and it’s beyond cleaning, you can also replace it.

Clean the area where the burner would go using a vacuum cleaner as well. It’ll be a while before you clean it again. So, be patient and try to get most of the dirt out of the combustion chamber.

After you’re done cleaning the main burner, put it back gently. It’s a good idea to replace the gasket at the burner access door to create a good seal in the combustion chamber.

Even if the main burner wasn’t the main issue here, there’s no waste of work here. You should inspect and clean the main burner once or twice a year to increase the longevity of your water heater.

Hopefully, you’ll have a nice and steady blue flame after cleaning the burner. Air in the gas lines can also cause this issue with the burner. Consult a qualified technician to purge the air from the gas lines if needed.

If you still get a yellow flame, it’s time to turn your attention to the restrictions in air inlet openings. You may have placed an object close to it and that blocks the openings.

There should be at least 1 inch of clearance between the air inlet openings and another object. So, if you’ve placed anything next to it, locate the object in another area.

Finally, you have to make sure that there is room for sufficient combustible air to enter the heater. Don’t install the area in a confined space. Three must be more than 50 cubic feet per 1000 Btuh of clearance for the heater. Once you take care of things, you should have a steady blue flame.

05. The Pilot Won’t Light

Lighting the pilot is the first step to using your water heater. Once the pilot is lit, it can ignite the main burner and you’ll start getting hot water. But if there is no pilot light, you won’t get any new hot water.

The primary reasons why the pilot won’t light are:

• Not correctly lighting the pilot.
• Clogged pilot burner orifice.
• Pinched or clogged pilot burner tube.
• Air in the gas lines.

How To Fix:

It’s most common for the pilot to not come on when the user fails to follow the pilot lighting instructions properly. As you’re reading this guide, that won’t be you. Before I show you how to light the pilot correctly, here are some additional tips to help you out:

• Never try to light the pilot by hand as the gas heater has a piezo-electric ignition system.
• Smell for gas before lighting the pilot. If you smell gas, refrain from lighting the pilot and call an expert immediately to handle the situation.
• Never use tools to turn the gas control knob. Always use your hands to turn the knob as tools can cause damage to it.
• Don’t try to light the pilot on a heater that has been flooded.

How To Light The Pilot In A Rheem Gas Water Heater?

With those tips out of the way, you can follow these steps to light the pilot on your Rheem gas water heater:

1. Turn the gas control knob to the “Off” position and wait for a few minutes to clear out any gas from the system. Take off the outer door of the heater so that you can look at the pilot and you can be aware of what’s going on.
2. Locate the igniter button that’s placed right below the gas control knob. Turn the gas control knob to the pilot position. Then, press and hold the knob all the way in. As you hold down the gas control knob, press the igniter button several times until the status light starts blinking.
3. If the status light starts to blink, verify that the pilot is actually lit by looking at the viewport. If the status light doesn’t blink, that means the pilot isn’t lit. In that case, you can repeat the above steps again to light the pilot.
4. If the status light doesn’t come on even after multiple attempts, there could be other issues with your pilot light. You can call a technician or keep on reading as we’ll solve some common pilot light issues.
5. Once the pilot is lit, you can let go of the gas control knob. It should pop right out and then, you can turn it to set your desired temperature. If the knob doesn’t pop out, you have to consult a technician.

Hopefully, that clears up how you can light the pilot and when you should seek professional help. If the pilot orifice or the pilot tube is clogged, it’ll have to be cleaned. At times, cleaning won’t do the trick and you’d have to replace the pilot assembly.

You can consult a qualified technician to replace the pilot assembly if you don’t know how to do it yourself. If there’s air in the gas lines, the technician can help you out with that too, and purge the air from them.

06. The Pilot Won’t Stay Lit

Another issue you could be facing with your heater’s pilot light is that it won’t stay lit. Once you let go of the control knob, the pilot is supposed to stay lit. But if the pilot light goes off after you let go of the gas control knob, that’s a problem that’ll lead to no hot water.

The main reasons why the pilot won’t stay lit are:

• The thermopile is defective or disconnected.
• Faulty safety magnet device.
• The gas control thermostat shut-off device was tripped.
• The combustion shut-off device was tripped.

How To Fix:

First, check if the thermopile wiring was disconnected. The wiring should be firmly connected to the connectors. If the wiring was disconnected, you can simply attach it again to solve the issue.

If the wiring is tight, it’s possible that the thermopile is faulty.  In that case, the thermopile will have to be replaced. You’ll have to remove the main burner,  isolate the thermopile, and replace it. You can do it yourself or hire a qualified technician to do it.

If a faulty safety magnet device is causing the issue, the gas control thermostat needs to be replaced. The connections to the gas control thermostat will have to be removed before you can replace it.

I have a detailed guide on how you can replace the thermostat yourself. Check out my Rheem gas water heater thermostat troubleshooting guide to learn all about it. Again, the choice is up to you. You can always hire an expert if you don’t feel like doing the task yourself.

The gas control thermostat will also have to be replaced if the thermostat shut-off device was tripped. If it’s the combustion shut-off that was tripped, hire a qualified technician to solve the issue.

Besides all that, the pilot light can also keep going out in your Rheem water heater. There could be several reasons behind it. Check out my Rheem water heater pilot light-outs guide to know more about this topic.

07. Main Burner Won’t Light Or Stay Lit

First of all, the pilot light must be lit for the main burner lighting to even be a consideration. So, the main burner not lighting up can also be caused due to the same issues that won’t light the pilot.

If your pilot won’t light or stay lit, solve it first following the two previous sections. Then, you can move on to the issues that won’t ignite the main burner.

The reasons why the main burner won’t light or stay lit are:

• Wire connections aren’t completely secure.
• The damper is not opening.
• The combustion shut-off device was tripped.
• Faulty gas control thermostat or tripped gas control shut-off device.

How To Fix:

First, inspect all the wiring connections in your heater. All of them must be tight for the heater to work properly. The heater is an integrated unit and if any of the wires come loose, the main burner may not light.

You can hire an electrician if don’t want to do it yourself. Once you tighten all the wire connections, check if the main burner works. If it does, you’ve solved the problem. Otherwise, you need to keep on diagnosing.

Secondly, you have to check whether the damper is opening. If it’s not opening, it could be due to loose wire connections as well. You’ll have to tighten the connection in that case.

However, there could also be issues with the flue damper installation. The flue damper switch can also be faulty. Two flashes with a three-second pause on your gas valve indicate this issue. You’ll have to replace the flue damper assembly in these situations to solve the issue.

You already know what to do about the other issues from the previous sections. Here’s a reminder – consult an expert if the combustion chamber was tripped. If the gas control thermostat is faulty or the shutoff device is tripped, the thermostat will also have to be replaced.

08. Water Is Too Hot

The hot water coming out of the faucet is a serious issue as it can even cause scalding. So, you need to become immediately aware and take action if you’re facing this problem.

When the water is too hot, this issue is caused is usually caused by one of the two following reasons:

• The thermostat is set too high.
• The thermostat is faulty.

How To Fix:

If someone has accidentally set the thermostat too high, you can dial the temperature down. Just adjust the control knob to your desired temperature setting and the problem will be solved. I’ve already shared the temperature guide so that you can set your thermostat to the right temperature.

But it’s also possible that the gas control thermostat itself is faulty. In that case, you’ll have to replace it with a new one. Once you do these things, you should get normal hot water from your heater without any issues.

09. Noise From The Relief Valve

Hearing a popping or draining noise from the relief valve is never a good sign. It indicates the build-up of pressure in the tank due to the thermal expansion in a closed system.

How To Fix:

As it’s a serious issue, you don’t have to do anything here. Don’t even attempt to operate the valve as it can cause more issues. Consult an expert immediately and stop using your heater in the meantime until this issue is resolved.

10. Rumbling Noise

It’s common to hear a rumbling noise from your water heater when sediment has built up in the tank. If you live in an area where hard water is supplied, you’ll face this issue more often.

As the minerals settle on the bottom of the tank, it makes a rumbling noise. The water will also start to turn brownish and smell bad if you don’t do something about it soon.

How To Fix:

Thankfully, fixing this issue won’t take much work. All you have to do is drain your tank and it’ll be solved. Follow these steps to drain the tank:

• Close the main gas shut-off valve to cut off the gas supply to the water heater.
• Open a hot water faucet so that the tank gets filled with cold water. It’ll protect you from a scalding injury.
• Wait for the tank to cool down and turn off the cold water supply.
• Open a hot water faucet to relieve the pressure from the system.
• Attach a garden hose to the drain valve and place the other end where you want to get rid of the water.
• Open the drain valve and wait until the tank is drained.

So, that’s how easy it is to drain the water from your tank. Once that’s done, you’ll reverse engineer the above steps and turn on the gas valve. You may have to do it once or twice a year depending on the hard water that’s supplied in your area.

What To Do When You Have A Bad Drain Valve?

You won’t be able to drain the water from your tank if you have a bad drain valve. The most obvious sign of a faulty drain valve is when it’s leaking. It’s common for plastic drain valves to break often and go bad.

Besides that, the drain valve could have terrible water flow and take a long time to drain the water. It could also not drain any water at all. All these situations point to a drain valve that has outlived its utility.

You need to replace the drain valves if you’re facing any of the problems stated above. Check out my Rheem drain valve replacement guide to learn how you can do that in detail. Hopefully, the rumbling noise will go away once you’re done with the replacement procedure.

11. Water Leaks

I’ve already gone over leaks from the hot water faucets. If you leave any of them open, the hot water will go out through them. So, you’d get less hot water when you actually need it.

But a more dangerous form of water leak is when the link originates from the heater itself. You’d get very little hot water when there’s a leak within your water heater.

Sometimes, you’d see a puddle of water around your water heater when there’s a leak. There are some common problem areas that are responsible for most water leaks. Some of those points are:

• The pipe connections are at the top of the tank.
• The drain valve.
• The T&P relief valve.
• Gas control thermostat.
• Inner tank.

How To Fix:

The right solution depends on the leak source. For example, if the leak is coming from the pipe connections, it would most likely be an easy fix. You’d have to tighten the leaky pipe connection and that would do the trick.

But the worst-case scenario is when the tank is corroded from the inside. In that case, you’d have to replace the entire tank. So, upgrading to a new heater altogether may make more sense for you in such situations.

You’d have to check all those points and feel for the water leaks if it’s not visually clear. I have a dedicated guide on stopping Rheem hot water leaks that’ll walk you through how you can solve this issue.

12. Failed Ignition Lockout

Your water heater often goes into lockout mode if it has tried to light up multiple times and failed. There could be many reasons behind this issue. However, the most common culprits are:

• Gas supply issues.
• Flue damper issues.
• Tripped thermal cutoff device.
• Pilot light issues.
• Defective gas control thermostat.
• And more

How To Fix:

The right fix depends on the problem that’s causing the issue. If it’s due to the lack of gas supply or bad gas pressure, you’d have to correct it. If there’s anything wrong with the pilot light, you’d have to find out the root problem and fix it.

I have a dedicated guide on getting the Rheem water heater out of lockout mode that covers these problems and solutions in detail. Check it out and you’ll find everything you need to know on how you should tackle this issue.

What Does It Mean When Your Rheem Water Heater Has No Status Light?

The status light in your Rheem water heater only comes up when the pilot in your water heater is lit. So, if the status light isn’t lit, it means that the pilot isn’t also lit.

The obvious solution here is to relight the pilot. When you light the pilot, the status light should start flashing again. If the status light starts flashing and calls for heat, that indicates normal operation of the water heater.

But what if you can’t relight the pilot even after following the right instructions? It means something is wrong with your heater. The most obvious culprit here is gas supply issues. If there’s no gas supply, the pilot won’t light no matter how many times you try.

Besides that, lack of air supply and pilot assembly issues can also cause this problem. The other scenario is that the pilot is lit but the status light still wouldn’t come on. That usually happens when you have a bad thermopile that doesn’t read the pilot flame.

However, a faulty gas control valve can also cause this issue. There are a lot of potential culprits here. Luckily, I have a dedicated guide on this topic for you. Check out my guide on fixing Rheem water heater status light won’t turn on to learn more about the solutions to this problem in detail.

Rheem Water Heater Blinking Light Codes [Blue Flashes]

There are certain gas control valves that blink blue even when something is wrong with your heater. Here’s the type of gas control valves that do that:

Before getting into the errors, let’s talk about how you can identify normal operations in such water heaters. If you see a short flash every four seconds, it means that everything is fine and the desired temperature has been achieved.

Secondly, you may also see the status light alternate between bright and dim. It also means normal operation. The only difference here is that the desired temperature hasn’t been reached yet and the heater is calling for heat. With those out of the way, let’s look at the error codes now.

i) One Flash

Seeing one flash on your Rheem gas water heater means that the flame signal is low. The most common culprits behind it are pilot light or gas supply issues. The pilot light issues are restricted pilot tubes, carbon deposits on the pilot electrodes, and damaged pilot igniter wires.

You’d have to check out the gas supply first and make sure everything is okay there. Then, inspect the pilot assembly and find out what’s wrong. Once you find the culprit, replace the faulty component and that would get the error code to go away.

ii) Two Flashes

The two flashes error code indicates that the system is in lockout mode due to the flue damper switch being stuck closed. The common culprits here are bad flue damper wiring or a faulty flue damper assembly. You’d have to diagnose the root cause behind this issue and solve it.

iii) Three Flashes

This error code is awfully similar to the last one. When the status light in your Rheem water heater flashes three times, it means the flue damper switch is stuck open. The main reasons behind this error code are:

• Not installing the flue damper properly.
• Defective flue damper switch.
• Incorrect wiring or connections.
• Bad flue damper motor.
• Obstructions in the damper opening.

You’d have to inspect these potential causes one by one until you find the culprit. Then, you’ll have to take the right steps to fix it. Luckily, I already have a guide on it for you. Check out my post on fixing Rheem water heater blinking three times for more detailed information to clear the code.

ix) Four Flashes

Whenever the thermal cutoff device in your heater gets tripped, the status light will blink four times. Your heater won’t run in this condition as the gas supply to the heater will be cut off.

The main reason this error code occurs is when the tank isn’t completely filled with water. Besides that, the thermal well in the gas control thermostat could be faulty. The gas control valve could also be defective.

You can just fill the tank if it isn’t already filled with water. Then, you can try resetting the thermostat. If that doesn’t work, you’d have to most likely replace the gas control valve. Visit my guide on fixing the Rheem water heater flashing four times to learn how you can erase this error code in detail.

v) Five Flashes

This one is a rare but serious error code. It occurs when the pilot or the main burner valve fails to open. In some cases, both of them may not open. It usually happens due to a bad gas control valve. You’d have to replace the gas control valve to clear this error code.

vi) Six One Flashes

The six-one flashes error code means the unit has failed to light. So, either the pilot won’t light at all or will be unstable when you see this error code.

The six-one error code is similar to the one flash error code and is caused by the same reasons. You can solve it by following the same steps you would take to clear the one flash one error code.

vii) Six Two Flashes

Besides the two and three flashes error codes, another code that represents flue damper issues is the six two flashes code. It means the flue damper switch is opened. It occurs due to incorrect installation, faulty wiring, or a defective flue damper switch. You already know how to deal with these issues by now.

viii) Six Thee Flashes

When you see the six three flashes error code, it means that the flame is lost and the system has gone into lockout mode. It occurs mostly when the pilot flame goes out in the middle of the operation of the heater. The primary causes behind this error code are:

• Restricted or damaged pilot tube.
• Carbon deposits on the pilot electrode.
• Damaged pilot igniter wire.
• Gas supply issues.
• Restricted or blocked air supply to the combustion chamber.

You’d have to inspect these components one by one until you find out what’s causing the error code. You can visit my Rheem water heater 6 3 flashes error code guide to learn how you can erase this error code in detail.

ix) Six Four Flashes

Seeing the six four flashes error code means that the flame is out of sequence and the heater has gone into lockout mode. It usually happens when the gas control thermostat is stuck open. You’d have to replace it to solve this issue.

x) Seven Flashes

The main reason why the seven flashes error code pops up on Rheem gas water heaters is when flammable vapors are detected around the heater. The flammable vapor sensor is a sensitive device that can easily get triggered by paint fumes or toxic chemicals.

So, that’s what may have caused the FVS to trip and caused the error code. Besides that, a faulty FVS or gas control thermostat will also cause this code.

However, the first thing you should try is to reset the flammable vapor sensor if this error code comes up. Visit my Rheem Flammable Vapor Sensor reset guide to learn how you can reset the FVS in your water heater.

You should explore the other solutions only if resetting the FVS doesn’t work. I have a dedicated guide on solving the Rheem water heater 7 flashes code. You should check it out to learn how you can solve this problem in detail.

xi) Eight One Flashes

The eight one flashes error code is similar to the seven flashes code. It also occurs due to issues with the flammable vapor sensor. But when this code comes up, there are higher chance that the FVS is faulty.

Besides the FVS itself being bad, there’s the possibility that its wiring is loose and it hasn’t made a good connection. So, you should tighten the connection at first. If that doesn’t work, you should test the FVS and replace it if it’s bad.

Luckily, I have a guide for you that’ll show you exactly how you can do that. Check out my post on fixing Rheem water heater eight one flashes to learn more about testing and replacing the FVS. Hopefully, you’ll be able to clear this code after following my guide.

xii) Eight Two Flashes

Whenever there’s a fault with the energy cut off device, this eight two flashes error code will come up. It usually happens due to bad wiring connections to the thermal well or a faulty thermal well.

First, inspect the wiring connection. If it turns out to be loose, tighten it to fix the issue. If that doesn’t work, the thermal well is most likely at fault. Replace it to solve the issue.

xiii) Eight Three Flashes

The eight three flashes error code comes up when a fault is detected within the electronics circuit. It occurs when the thermal well or the gas valve is faulty. Depending on what’s causing the issue, you’d either have to replace the thermal well or the gas control valve to solve this error code.

xiv) Eight Four Flashes

When you see the eight four flashes code come up in your heater, it means something is wrong with the gas control valve. You can try resetting it first and see if that solves the issue.

If that doesn’t work, it means that the gas control valve has most likely gone bad. You’d have to replace it to clear the error code in that case.

So, that was all the blue error codes in a Rheem gas water heater. If you want to learn about them in detail, I have a dedicated guide on it too. Visit my Rheem blue blinking light codes guide for more information on them.

Rheem Water Heater Error Codes [Red Flashes]

There are Honeywell gas valves in which the status light blinks red to indicate an issue with your water heater. It’ll keep flashing the error code, pause for 3 seconds, and then flash again. Here’s the type of gas valves that blink red when there’s an error code:

I’ll take a quick look at the common error codes, their meanings, and fixes in this section.

i) 2 Flashes

This code means that the thermopile voltage is too low even though the pilot is lit. More often than not, it comes up when the thermopile isn’t properly connected to the gas control valve.

So, check the connection and tighten it if it’s too loose. Secondly, there could be other issues like a faulty thermopile or pilot assembly. The thermopile wires could also be damaged. Check all these things and take corrective actions. Visit my Rheem gas heater flashing twice guide to learn more about the solutions.

ii) 4 Flashes

The four flashes error code pops up on a Rheem gas water heater when the high water temperature limit gets tripped. It’s a safety mechanism meant to protect the users from scalding. The gas supply to the heater gets cut off whenever the high temperature limit gets tripped.

Check out my guide on Rheem water heater flashing red light 4 times to learn more about this issue. You’ll learn about a handy trick to clear the error code in that guide. If that doesn’t work, you’d most likely have to replace the gas control thermostat to solve this issue. 

iii) 5 Flashes

When you see 5 red flashes on your Rheem hot water’s gas control valve, it means the water temperature sensor has failed. So, the water can get too cold or too hot in that scenario. You’d have to replace it to solve this issue.

iv) 7 Flashes

If you have a bad gas control valve, the status light will blink seven times. You’d have to replace the gas control valve in that case. Check out my Rheem water heater blinking seven times to learn how you can fix this issue.

v) 8 Flashes

Your Rheem water heater blinking red eight times indicates that there’s a false pilot flame signal. It means that the pilot light isn’t being sensed when it’s on or it’s being sensed when it’s off.

You’d have to diagnose the thermopile and the pilot assembly to figure out what’s wrong. Once you find the faulty component, replace it with a new one and that should solve the issue.

vi) 9 Flashes

This code represents that the chamber sensor has failed. The chamber sensor could either be dirty or completely damaged. You can clean the chamber sensor if it’s dirty. But it’s better to replace it altogether for a long-term solution.

If the chamber sensor isn’t at fault, the gas control thermostat is defective. So, you should test the chamber sensor before replacing it. Visit my fixing Rheem hot water chamber sensor failure guide to learn how to test and replace it. The error code will go away if you take the right actions.

vii) 10 Flashes

The status light in the Rheem gas water heaters blinks ten times due to chamber temperature shutdown. This code indicates that the temperature inside the combustion chamber got so high that the heater had to shut off.

The most obvious reason behind this issue is when the air supply to the chamber is restricted. It happens when the air inlet openings are clogged or the burner screen is dirty. So, make sure you inspect them thoroughly and clear the obstructions so that there’s proper airflow to the combustion chamber.

So, that was a rundown of the error codes you’d see in your Rheem gas water heater. Check out my Rheem red light error codes guide if you want to know more about these error codes and their solutions in detail.

How To Reset Rheem Gas Water Heater?

You may expect to find a reset button in your gas water heater. Sorry to burst your bubble but there are no such buttons in Rheem gas water heaters. Don’t worry, that doesn’t necessarily mean that you can’t reset the gas heater.

There are certain gas control valves that can be reset. Rheem gas water heaters with Honeywell gas valves that flash blue light and White Rodgers gas valves can be reset. You can follow these steps to reset the Rheem water heaters with a Honeywell gas valve:

1. Turn off the gas control valve and unplug the heater from its power source.
2. Wait for a minute and rotate the gas control knob to the “Low” position while the heater is turned off.
3. Restore the power supply to the heater and turn the gas valve back on.
4. Rotate the gas control valve in this exact sequence within 30 seconds: Low To High, High To Low, Low To High, High To Low, Low To High, High To Low, and Low To High.
5. Once you complete the seven rotations, as shown above, the gas control valve will be automatically reset.
6. Set the gas control knob to your desired temperature after that. The burner will ignite if there are no further issues with your water heater.

That’s how easy it is to reset a Rheem water heater. If you want more detailed instructions on how to do it, visit my Rheem gas water heater resetting guide. You’ll also find how you can reset heaters with a White Rodgers gas control valve there.

Hopefully, resetting the heater will clear whatever error code you’re facing. If that happens, you can enjoy the hot water from your heater. But if the code remains, you’ll have to find the underlying issue that’s causing the problem and fix it.

Rheem Professional Prestige Maximus Gas Water Heater Troubleshooting Guide

A lot of what I’ve discussed applies to this water heater as well. But this heater deserves a troubleshooting guide as there are some issues unique to it. Let’s have a quick look at them.

01. Display Not On

The main reasons why the display isn’t on are either there is no power to the unit or the control board harness was disconnected.

Press the On/Off switch to turn on the power to the water heater. Make sure that the circuit breaker is working properly and that there are no other electrical issues. Inspect the fuse on the ignition control board and replace it if it’s blown.

If the wiring harness of the control board was disconnected, you have to reconnect it. Attach the wire harness to J4 on the ignition control board and make sure that the connection is nice and tight.

02. Blower Won’t Run

The blower won’t operate when there’s no power to the blower motor. Make sure that all the harnesses are connected firmly to the blower. If any of the connectors are damaged, they’ll have to be replaced.

03. The Main Burner Won’t Light Or Stay Lit

The reasons I had previously discussed why the main burner won’t light are also applicable here. But there are some additional issues you should be aware of if the main burner doesn’t light up in a Rheem Prestige Maximums heater.

Some of these issues are:

• Pressure switch issues.
• Clogged inlet or exhaust vent pipe.
• The burner flame isn’t contacting the sensor rod.

The pressure switch can either be kinked or the area around it can be dirty. The pressure switch will also shut off the heater if the inlet and outlet vents are blocked. To make matters worse, the switch itself can also get kinked and disconnected from the connectors.

So, clean the area around the pressure switch as well as the inlet and exhaust pipes to remove the debris in them. Then, inspect the pressure switch is connected properly. If the connection is tight and the switch still isn’t working, you’ll have to replace it.

Finally, if the burner flame isn’t reaching the sensor rod, you can consult a technician to see how the flame can be rectified. Doing all these things along with the previous fixes should give you a consistent flame from the burner.

How To Maintain A Rheem Gas Water Heater?

Maintaining your water heater properly is highly important to ensure the well-being of your water heater. There are a few key maintenance tips you should always follow to make sure your water heater stays in top-notch condition. Some of those tips are:

01. Periodically Flush Your Water Heater

As you keep using your water heater, sediments will pile up on the bottom of your tank. You’d have to flush the heater at periodic intervals to remove them. Check out my guide on flushing a Rheem water heater to learn how you can do it in detail.

02. Check The T&P Valve Manually

The T&P valve makes sure that the pressure or temperature inside the tank never gets too high. If the pressure were ever to get too high, the entire tank could explode. So, operate the T&P valve every six months or so to make sure that it’s working correctly.

03. Inspect The Anode Rod

The anode rod gets damaged itself and protects the tank. It attracts the sediments towards itself so that they don’t damage the tank. But the anode rod gets destroyed with time due to those sediments. So, you’d have to inspect the anode rod from time to time and replace it when it’s depleted.

04. Keep The Area Around The Heater Clean

The area around the heater should be clean at all times. If there are paint fumes or toxic chemicals around it, the FVS will get tripped and the heater will go into a lockout mode.

If there are objects around the heater, it could restrict the airflow to the heater as well. It won’t burn efficiently when that happens. So, give your maximum efforts to make sure that the heater is clean at all times.

05. Check The Venting System

Inspect the vent pipes once a year and make sure the connections are secure. If there are any obstructions in the venting pipes, remove them. If you find any soot in the vent pipe connections, consult a technician right away to fix it.

06. Inspect The Burner Assembly

The main burner and pilot assemblies can get clogged after years of use. You should clean the main burner from time to time as it’ll always have carbon deposits. The more often you clean the burner assembly in your water heater, the better it will perform.

So, those were the maintenance tips in short. If you want to know more about them in detail, visit my dedicated guide on maintaining Rheem water heaters. You’ll also learn about how you can replace the anode rod in that guide. So, check it out and learn how you can increase the lifespan of your water heater.

Rheem Water Heater Troubleshooting [Electric Units – Full Guide]

The most common issue you’d face with your Rheem electric heater is not getting hot water. I can tell you that from my own experience of working on many electric heaters over the years.

It can be caused by issues like no power supply, a tripped ECO, etc. However, there are plenty of other problems that can occur with your water heater.

I’ll discuss the following problems in this ultimate Rheem electric water heater troubleshooting guide:

• No hot water.
• Insufficient hot water.
• The water is too hot.
• Discolored water
• Bad smelling water
• And more.

Don’t worry, I won’t just discuss the problems and leave you hanging. You’ll learn about the solutions to each of these issues. So, let’s dive right in!

01. No Hot Water

In my experience, the number one reason you get no hot water from your water heater is when the heater has no power supply. It could be due to switching off the electrical breaker, tripping the circuit breaker, or improper wiring.

Secondly, the ECO can also get tripped and cause this issue. The ECO is a safety device that shuts off the heater’s operation when the water temperature is too hot. It turns off the heater to protect the user from scalding.

If either of the heating elements has failed, it can also lead to the no hot water issue. It’s not a likely issue to occur in new electric water heaters. But you should consider it if you’ve been using your heater for at least over a year.

How To Fix:

The right fix to solve the no hot water problem depends mainly on what’s causing it. Here are the solutions to each of the potential issues that could have caused this issue.

i) No Power Supply

If you’re lucky, it’ll be a power supply issue that can be easily fixed. More often than not, a Rheem water heater is connected to a designated circuit breaker. Check if the circuit breaker leading to the water heater was tripped. If it was, you can flip it back to the “On” position to solve the problem.

The last thing you need to check to rule out power supply issues is the wiring. If it’s a new installation, then the electrical connections could have been messed up during the setup process.

Recheck the connections and consult a qualified technician if needed. If you find any loose connections, tighten them. If any of the wiring is damaged, you’ll have to replace the faulty firing to fix the issue.

There’s also the possibility that your Rheem water heater won’t turn on at all. It can also keep shutting off. The common culprits in those cases are also tripped breakers and wiring issues.

But it can also happen when the ECO gets tripped. Besides, a faulty thermostat and heating element will also cause this issue. So, check out my Rheem power supply issues guide to learn how you can solve this problem.

ii) Tripped ECO

If you have a tripped ECO, you’ll have to reset the heater to make it operational again. Follow these guidelines to reset your Rheem electric heater:

1. Turn off the power supply to the heater by flipping the circuit breaker to the “Off” position.
2. Remove the screws holding the upper access panel in its place and take it off.
3. Unfold the insulation and you’d have eyes on the reset button.
4. Press the red reset button and you should hear a clicking sound.
5. Place the insulation in its original position, fold the insulation back, and the access cover back on.
6. Flip the breakers again and turn on the power supply to your water heater.

So, that’s how you can reset a tripped ECO. If you don’t hear a clicking sound after pressing the reset button, it means the ECO wasn’t tripped. Something else is causing the issue in such cases.

If this is a regular occurrence, then you need to be alarmed. Remember that the ECO trips for a reason. You have to inspect the underlying cause behind it and fix it. Otherwise, you have a real risk of scalding and the heater can also get permanently damaged.

I have a dedicated Rheem water heater reset button guide to help you out with these issues. You’ll find out why the reset button doesn’t work and what you can do if it keeps on tripping. If you’re facing issues with the reset button, you should definitely check it out.

iii) Failed Heating Element

If you have a faulty heating element, you have no option but to replace it. But before I get into the replacement procedure, you should know how to check the heating element.

You’ll need a digital multimeter to test the heating element. Luckily, I have a guide where you can learn to do both of these things.  Check out my guide on Rheem electric heater, not heating solutions to learn more about it in detail.

If your unit has two heating elements, make sure you test both of them. Either the upper or lower heating element could be at fault here. If the test reveals that you have a bad heating element, you should replace it.

02. Insufficient Hot Water

There are times when you’d get hot water but it won’t be hot enough. This issue can be just as annoying as not getting any hot water. Make sure that your electric water heater has power first before you move on to diagnose the issue any further.

If the heater has power, check whether someone has set the thermostat too low. The other potential culprit here is too many people using hot water at the same time. If the heater you’re using is undersized for your family’s needs, you won’t get enough hot water.

Besides those common issues, reversed plumbing connections or any leak in the hot water lines can also cause this problem. Finally, a melted dip tube or a damaged thermostatic mixing valve can also be the main reason why you don’t have ample hot water.

How To Fix:

Let’s look at each of the issues one by one. If someone has set the thermostat too low, you can just increase the temperature again. The temperature at the upper thermostat should be a little higher than the lower thermostat for optimal performance of the heater.

Next, limit the number of people using hot water at once by coming up with a plan with your family. If you make a shower schedule and adhere to it, you can manage the hot water demand and avoid this issue. If that’s not a possibility, you’ll have to upgrade to a bigger heater.

Check for leaks in the hot water side. Even a small leak can heavily reduce the amount of hot water going to the faucet. So, you’d have to replace the leaky pipe or faucet depending on what’s causing the issue.

If you want more detailed information on how to solve the above issues, I have a dedicated guide on this topic. Visit how to solve Rheem water heater not heating hot water to learn more about these things in detail.

03. The Water Is Too Hot

If you’re getting hot water with an extremely high temperature, I bet that you’ve set the thermostat too high. There are not too many other things that can go wrong and cause this issue.

There’s a rare chance that the heating element has shorted. When that happens, it’ll continue to heat the water even when the desired temperature is reached. But dollars to donuts – the thermostat is set too high.

How To Fix:

If the temperature is set too high, you’ll just have to adjust it. You’ll need a screwdriver to change the temperature settings on the thermostat unless you have a unit with a keypad. Follow these steps to change the temperature in your Rheem electric heater:

• Cut off the power supply to the heater.
• Remove the access cover and fold the insulation.
• Set the thermostat dial to the desired temperature.
• Unfold the insulation and place the access cover in its original position.

That’s how easy it is to adjust the temperature. Make sure you set the exact same temperature on both the upper and lower thermostats. The process is the same for both of them. Once you do that, you should get water at the right temperature and enjoy a hot shower.

04. Discolored Water

There’s a device called an anode rod inside the tank of your water heater. It has one job – to protect the heater from being corroded. It does so by attracting the sediments to itself and getting corroded first.

If you have water that has turned brown or rusty, the anode rod in your water heater has been depleted. It’s also a warning sign that the tank will get corroded soon if you don’t do something about it.

How To Fix:

If your anode rod is depleted, the fix is simple – you’d have to replace it. In fact, the anode rod is designed to get corroded. You just have to replace it at the right time.

When more than 6″ of core wire of the rod is exposed, it’s the perfect time to replace it. But when you have discolored water, that’s a good time too even though it’s a little late. Follow these steps to replace the anode rod:

Step 01: Drain The Tank

• Shut off the power to the heater at the circuit breaker.
• Close the cold water supply and open a hot water faucet to get rid of the system pressure inside the tank.
• Connect a garden hose to the drain valve at the bottom of the heater, open the drain valve, and drain the tank.

Step 02 – Remove The Old Anode Rod

• Locate the anode rod position on the top of the tank.
• Remove the cap of the anode rod and if you find any insulation, remove it using a flathead screwdriver.
• Use a socket wrench and turn the anode rod counterclockwise to remove it. Keep a rag at hand as there could be some seepage of water.
• Lift the anode rod out of the tank when it’s loose. Be cautious here as the metal part of the anode rod could be hot.

Step 03: Replace The Old Anode Rod

• Cover the threads of the new anode rod with Teflon tape and wrap it at least six times.
• Place the anode rod in the right position and tighten it using the socket wrench.
• Turn on the hot water faucet and the cold water supply.
• Turn off the hot water faucet after a minute and let the tank fill.
• If there’s no leak, you can place the plastic cover back on and complete the installation. If there is a leak, you’ve made a mistake somewhere and you have to redo the replacement.

So, it’s not difficult to replace the anode rod. Trust me, I’ve done it many times. You can do it on your own with the help of a few basic tools. Once you replace the anode rod, turn on the power to the heater and you’ll get clean water again.

05: Bad Smelling Water

Do you set the temperature of the hot water close to 120 degrees Fahrenheit? If you do, then the chances of the hot water smelling funny increase a lot. That’s because it’s the ideal temperature for bacterial growth.

The bacteria find the perfect environment for their growth inside the tank at that temperature. The smell is close to that of rotten eggs when this issue occurs. Typically, a bad anode rod can also be responsible here.

How To Fix:

You already know how to replace a bad anode rod if it’s depleted. But it may not always be the culprit as the bacteria could be causing it.

So, a good way to kill most of the bacteria and get rid of the smell is to set the temperature to 140 degrees Fahrenheit. Watch out and protect yourself from scalding by using mixing valves if you raise the temperature that high. Harming yourself to get rid of a bad smell isn’t worth it.

Another approach you can take to solve this issue is to replace the old anode rod with a special zinc rod. It’ll do a better job of killing the bacteria. But getting such an anode rod can breach the warranty. So, make sure you clarify it before taking further action.

Lastly, you can flush your tank with hydrogen peroxide to get rid of the bacteria. Just leave the solution for two hours and see if that helps. It’s good to repeat this process annually to keep the water from smelling bad again.

06. Water Leaks

Another common but annoying issue you may face with your Rheem electric heater is leaking water. More often than not, the main reason behind leaking water is also corrosion.

As water stays in the tank, sediments, and rust can form with time and develop cracks. The water leaks through the cracks. This issue isn’t only limited to the tank but can also occur at the valves and plumbing connections.

If you’re facing this issue in a newly installed heater, there may have been installation mistakes. If the heating element or any other important component is loose, there will be a water leak.

Besides them, the leak can also come from loose pipe connections. If they’re not properly sealed, water can leak from the top of the tank. Finally, the water can also leak from the T&P relief valve.

How To Fix:

You can locate the leak source by a quick visual inspection most time. But if that’s not evident, you can feel the potential culprit with your hands. If any of the components were leaking, you should feel water residue on them.

It all comes down to identifying the source of the leak and fixing it. If the heating element or any of the component was loose, it’ll have to be installed correctly to seal the leak. Make sure the heating element gasket isn’t cracked. Replace the gasket if it’s damaged.

The same goes for faulty valves and cracks in pipes. They’ll have to be replaced with new ones to stop the water leaks. If the pipe connections are loose, they’ll also have to be tightened to seal the leak.

That leaves us with cracks in the tank to check next. Unfortunately, there’s no easy fix for that one. You have probably been using your heater for a while if the tank is corroded and it’s time to say goodbye. You’d have to replace the tank to solve this issue and stop the water from leaking.

The same goes for the T&P relief valve. If it’s leaking, that means the connection is too loose. You’ll have to tighten it and stop the leak.

I have a dedicated guide on how to stop a Rheem water heater from leaking. You’ll find all the information you need with detailed instructions on how to stop the leak. Feel free to visit it if you’re facing this particular issue.

07. Tank Making Noises

Hearing a popping or rumbling noise coming from the tank indicates one issue – the build-up of scale. That could be either in the bottom of the tank or the heating elements. It could even be in both of them.

How To Fix:

You’ll have to flush the tank and clean the heating elements to solve this problem. You already know how to clean the tank using hydrogen peroxide as it has been discussed previously. You can also use a descaling solution to do this job.

You also have to clean the heating elements as scale has most likely accumulated on them as well. You know how to remove the heating element. Place it in a descaling solution and follow the instructions in the kit. Then, put the heating elements back in when they’re clean.

If you clean both the tank and the heating elements, the rumbling noise of the tank should go away. If it still remains, there could be severe corrosion in the tank. You’ll have to replace it to solve this issue.

08. Relief Valve Noises

If you hear popping noises from the relief valve, it indicates pressure build-up in the tank. It’s caused by thermal expansion in a closed system. As it’s a serious issue, you should proceed with caution here.

How To Fix:

I don’t recommend you attempt to solve this issue on your own. So, get professional help to fix this issue and do it as soon as possible. Otherwise, a serious issue could occur. Make sure you don’t plug the relief valve outlet while you wait for help to arrive.

09. Can’t Set The Temperature Past 140°F

This is an issue you’d only face on heaters that have a keypad or electronic control. Usually, the Rheem platinum and gladiator models have this component. You don’t have to worry about it if you own a unit like Rheem Marathon as it doesn’t have a keypad.

Now, the reason that you can’t set the temperature above 140°F in those units is because the keypad is locked. It’s done so that you don’t set the temperature too high and accidentally scald yourself.

How To Fix:

You have to unlock the keypad if you want to set the temperature higher than 140°F. All you have to do is press both the arrow buttons together for 3 seconds to unlock the keypad. You’ll be able to set the temperature up to 150°F by pressing the right arrow after unlocking the keypad.

Make sure you’re using thermostatic mixing valves to protect yourself from scalding if you set the temperature that high. You can lock the keypad again by pressing both arrow buttons for 3 seconds. You can toggle between locking and unlocking the keypad using this method.

10. Tripping Breaker

Sometimes, your Rheem water heater can make the breakers trip again and again. It could be an issue with the breaker itself. If you use a breaker that’s not of the right size for your heater, you could face this issue.

The breaker panel can also go bad if it has been used for a long time. You should also make sure that you’re not using the same breaker as your heater for other appliances. The breaker can easily get tripped if you do that.

If the breaker is fine, the issue could be with your water heater. The main culprits here are a faulty thermostat, defective heating element, water leaks, and wiring issues.

How To Fix:

Firstly, you’d have to take the circuit breaker and see if there’s anything wrong with it. If you can’t do it on your own, consult a trained electrician to help you.

If nothing is wrong with the circuit breaker powering your heater, one of the components in your heater could have gone bad. You’d have to check them one by one until you find the root issue.

Check out my Rheem heater tripping circuit breaker guide to learn more about these problems and their solutions. You’ll know how you can fix each of these issues in that guide. So, follow the fixes to keep your water heater from tripping again and enjoy the hot water you get from it.

11. Error Codes

Sometimes, the heater itself will tell you what’s wrong with it. You won’t have to spend a lot of time diagnosing the issue in those cases. The heater does that by showing error codes.

You won’t get error codes in all Rheem electric heaters. But some models like the Rheem Performance Platinum can show error codes to indicate the issue. Here’s a quick glance at the error codes you can encounter:

Solid Red Light – It could be due to water leaks, issues with WiFi connectivity, the shutoff valve not closing, and failure to restore configuration data.

1 Red Blink – You’ll notice the red light blinking once when either the lower thermistor has disconnected or completely failed.

2 Red Blinks – More often than not, it’s due to the shutoff valve being stuck. It can either be stuck in an open or closed position. Apart from that, this code will also appear when water is in contact with a wick or rope sensor.

3 Red Blinks – This error code indicates that the tank is not completely filled with water. It’s not safe to operate the heater in this condition as it can damage the heating element.

4 Red Blinks – When any of the heating elements have failed, this error code can come up. It can also come up when the element wires have been disconnected or the ECO has been tripped and needs to be reset.

4 Red Blinks –  This error code indicates several potential errors with your heater. That includes issues with the lower element relay, lower temperature conversion, temperature protection, and upper thermistor.

How To Fix:

The right solution depends on the issue. You can refer to your owner’s manual or talk to a qualified technician about these problems. None of the issues are too complicated to solve and hopefully, you’ll get a quick solution.

Sometimes, you’d have to replace damaged components. But you can always get an expert to do it for you if you don’t feel comfortable doing it yourself.

Luckily, I have a dedicated guide on this topic for you. You can learn about how you can solve all these error codes in detail in that guide. Visit my Rheem electrical heater red light flashes guide to sort this problem out.

How To Maintain Rheem Electric Water Heaters?

If you maintain your water heater properly, it’ll last longer for many years to come. So, you should always follow the right practices and do as much as you can to maintain your water heater.

You may be wondering what are the main things you should do to maintain your water heater. Here’s a quick overview of those things:

i) Flush Your Water Heater

As you keep using your water heater, sediments will pile up on the bottom of the tank. You need to flush the heater to get those sediments out. If you don’t do that, the anode rod will be depleted and your tank will begin to corrode.

So, the tank will develop cracks and you’d have to replace the entire heater. Based on the hard water in your area, you may have to flush the tank once or twice a year.

Worried about how to flush your tank properly? Don’t worry, I got your back. Check out my Rheem heater flushing guide and execute all the steps mentioned there to do this job properly.

ii) Replace Anode Rod When Needed

The anode rod protects the tank by sacrificing itself. It attracts all the sediments towards itself so that the tank remains protected. So, the anode rod gets severely corroded with time.

That’s why it’s important to replace the anode rod in time. Check out my guide on maintaining Rheem water heaters for detailed instructions on how to replace the anode rod. Besides that, you’ll also find out more about all the important maintenance tips in detail.

iii) Operate T&P Valve Manually

You should operate the T&P valve from time to time to make sure it works properly. The T&P valve plays a big role in making sure that the pressure or temperature inside the tank doesn’t get too high.

If it ever were to get very high, the tank could explode. That’s why it’s so important to confirm that the T&P valve works well. If the T&P valve doesn’t work properly, you’d have to replace it with a functional one.

How To Change Temperature In Rheem Electric Water Heaters?

Adjusting the temperature on electric water heaters is comparatively harder than on gas and tankless heaters. In gas water heaters, you can rotate the temperature adjustment knob. In most tankless units, you can change the temperature using the keypad.

But it doesn’t quite work that way in electric water heaters. You’d have to take off the access covers and remove the insulation to access the thermostat. Then, you can set the temperature using a flathead screwdriver.

Another thing to keep in mind is that there are two thermostats in most electric water heaters. So, you’d have to set similar temperatures on both of them. They can’t be far apart from each other.

With all that said, you can follow these exact steps to adjust the temperature in your Rheem electric water heater:

1. Turn off the circuit breakers and stop the power supply to the water heater.
2. Remove the access cover and unfold the insulation of the first thermostat you want to adjust. When you have eyes on the thermostat, you can turn it using a flathead screwdriver. You’ll see the temperature readings and you can set the thermostat according to that.
3. Similarly, adjust the other thermostat following the same method if your water heater has two heating elements. It’s a good idea to set the temperature on the upper thermostat a little higher than the lower thermostat.
4. Turn on the power supply back to the heater and wait for a while for the water to get your desired temperature.
5. Test the temperature of the hot water once it reaches your desired temperature. If it’s to your liking, there’s no need to do anything else. If it’s too hot or too cold, you can adjust the temperature accordingly again. Keep at it till you find the right temperature for you.

You should keep in mind that there are also electric heaters with an external keypad. You won’t have to do all this work to change the temperature on those units. You can easily turn the temperature up and down using the designated buttons on the keypad.

There’s still a lot I haven’t talked about when it comes to adjusting the temperature. It’s always better to set the upper thermostat a little higher than the lower thermostat. You can also keep them the same. But it’s not a good idea to set the lower thermostat higher than the upper thermostat.

You may also be interested in learning about the ideal temperature for your electrical water heater. I cover all these topics in my Rheem electric water heater temperature adjustment guide. Check it out to learn more about these things if you’re interested.

Rheem Tankless Water Heater Troubleshooting [The Ultimate Guide]

The most common problems you’d face with your Rheem tankless water heater include:

• Not turning on
• No hot water
• Water isn’t hot enough
• No power to the remote 
• Water leakage
• Heater is overheating

But fear not, based on my extensive years of hands-on experience with Rheem water heater, I’ll share the ideal fixes for this issue.  So, let’s dig deep into the solutions.

How To Troubleshoot Rheem Tankless Water Heater [Quick Overview]

Before embarking on this adventure, let me walk you through the quick table below, highlighting major Rheem tankless water heater problems with their probable reasons:

Before embarking on this adventure, let me walk you through the quick table below, highlighting major Rheem tankless water heater problems with their probable reasons:

Most Common Rheem Tankless Water Heater Problems [Easy Solutions]

Now let’s dive deeper and explore all the effective solutions to the most happening Rheem tankless water heater issues: 

01. Water Heater Is Not Turning On

If your Rheem tankless water is failing to turn on, several factors would be responsible here:

• Degradation in power supply
• Improper voltage supply to the unity
• Defective remote control thermostat
• Defective PCB

Besides, in my gas-powered model, I found an interruption in the gas supply as one of the major culprits to blame for the unit not turning on after my long trying.

How To Fix:

As for the leading suspect, inspect the tankless unit for a faulty power supply. However, if you have a gas-operated model, it requires fluent power to run effectively. 

If the power has gone out, you’ll never expect to turn on the heater. Anyway, in case of degradation in the power supply, check out the following:

• Check for a tripped circuit breaker and reset it
• Replace the blown fuse
• Inspect all the wiring for many cut, chewed, or burnt out connection
• Check for faulty or damaged switchboard and lug the unit to a different power outlet
• Ensure a properly grounded 120 VAC/60 Hz power supply to the heater

When all is done and still the unit is not turning on, be sure the heater is in maintenance mode. You can simply activate your heater while in Maintenance mode following the instructions in our effective Rheem troubleshooting guide. 

Last, but not least, check for faulty remote control and PCB and replace the faulty parts. 

02. No Hot Water Is Coming

If your Rheem tankless water heater not heating at all, a higher possibility is you’ve set the temperature too low. If that is not so, then the chances are the water flow to the unit is not correct. 

Besides, using too many hot water fixtures at a time or wrong adjustment of the mixing valve may also be responsible here. 

These are the common reasons to blame for no hot water in a Rheem water heater. Now let’s have a detailed insight into why Rheem gas and electric tankless water heater not getting hot.

 #Rheem Gas Tankless Water Heater No Hot Water

The gas-powered water heater mainly relies on fuel supply. Thus, interruption in gas supply affects its overall functions. Besides, a clogged water filter, scaled heat exchanger, or defective mixing valve won’t let your water heater reach the desired temperature.

How To Fix:

• As for the first step, inspect the water heater for a faulty power supply. Make sure there is sufficient fuel in the LP tank, or that you have a good supply of gas in the unit.
• Remove the obstruction from the gas supply lines. Also, open the gas shut-off valve all the way.
• Check for clogged water filters and remove the stuck debris from the filter screen.
• Adjust the mixing valve of your faucets or replace it with a new one.
• If needed, flush your water heater.

#Rheem Electric Tankless Water Heater No Hot Water

In the case of Rheem electric water heater not getting hot, I bet the heating element in the system has stopped working. Rheem electric tankless water features two robust copper immersion heating elements that are designed to convert the electrical energy into heat and heat the water.

Anyway, this time, inspect the heating elements to see whether they are in working condition. For instance, test the continuity of the heating element. If the results show negative, you need to replace them.

Contact a professional for further replacement discussion.  

03. The Water Heater Is Heating But The Water Temperature Isn’t Hot Enough

While using my Rheem tankless water heater, it’s quite a common phenomenon to me that the unit is operating well, but the temperature isn’t as hot as I want! So, that’s the case, I conducted some research and identified several key factors to focus on. These include:

• The set temperature is too low
• The flow rate is too high
• Incorrect wiring connection (Electric model)
• Improper voltage supply (Electric model)
• Mixing too much cold water

How To Fix:

Whenever you encounter such issues with your tankless model, follow the simple instructions to deal with it:

First up, head over to the remote control and set the temperature higher if it’s set too low. In many Rheem water heaters, it is even possible to set the temperature at 140 degrees F, though it isn’t recommended for home use. 

Next, check the water flow rate for your water heater to see whether it is too high. You can easily reduce the flow rate by installing a flow restrictor in the water liens. Inspect the anti-scald valve of your hot water faucet and adjust it to reduce the amount of cold water mixed.

Finally, if your Rheem electric water heater is newly installed, check for a cross-wiring connection in the system and fix it with the help of an electrician. 

Also, note that the heating elements on your water heater are designed for 240 volts. So check for lower voltages as well and upgrade it.

04. The Water Is Too hot

While operating, you may notice that your Rheem tankless water heater overheating. If there is not any major problem in the system, the issue is more likely related to the too-high temperature setting. 

Thus, as for the first step, stop operating your heater and check the temperature setting at the remote control. It’s best to adjust it to 120F or less. 

If the issue continues even after setting the temperature, this is the time you need to go deep to track down the major reasons. From my years experience, I’ve found a few reasons to include herewith:

• Low water flow as a very little amount of water is heating
• Faulty remote control
• Restricted airflow
• Scaled or cracked heat exchanger 

How To Fix:

First off, check for low water flow in your tankless system. For instance, head to the cold and hot water shut-off valves and check for restrictions. A restriction in either valve triggers the overheating. 

Also, open the shut-off valves and hot water faucets all the way to ensure fluent water flow to the unit.

When done, verify the airflow to the unit as restriction in the air supply leads to the system overheating. Look for something that is blocking the air supply and remove it.

Now, inspect the heat exchanger for scale buildup. If you are living in a hard water area, plugging up the heat exchanger fins with the mineral is quite obvious. Hard minerals buildup causes overheating since the heater has to work extra hard to heat the water.

As a solution, you need to descale and flush your water heater or replace the cracked heat exchanger. 

If the issue continues even after resolving all the above factors, get the remote control checked for mechanical faults by a professional plumber. 

05. Rheem Tankless Water Heater Keeps Shutting Off

While in operation, at times, I experience that my Rheem tankless keeps turning off even after everything looks fine. I’ve gone deeper to track down the facts and found a few notable factors responsible for this issue. That includes:

• Loose or damaged wiring connection
• System overload
• The water flow is not enough to activate the unit. 

Well! These are common reasons applicable to both gas and electric models. Now take a closer look at all the responsive factors for why a Rheem gas and electric water heater shut off randomly:

 How To Fix:

Start by inspecting the system for any loose or damaged wiring connection. Tighten the loose connection or replace the worn-out one. Next, verify whether the water flow rate in your Rheem water heater is enough to continue the operation. 

Generally, continuous operation of the water heater requires a minimum water flow rate of 0.25 GPM (1.01 LPM). Adjust the water level to the recommended level. Then, verify if the unit is going through system overload. 

To deal with this fact, close some hot water faucets and reduce the hot water demand.

After resolving all the above factors, if the system still fails to stay on, check for faulty gas and air supply in your Rheem tankless water heater. Ensure there is a sufficient gas supply in the unit to continue the operation. Also, the air intake and combustion elements should be free of any blockages. 

In the case of the Rheem electric water heater, replace the bad breaker and faulty heating element. Replace the defective parts.

06. The Water Heater is Beeping 

Rheem tankless water heater beeping is an alarming sign that there is something wrong going through the system. Your tankless water heater will beep mainly due to any of the following reasons:

• Leaking in the system
• You are using too many hot water fixture that is overloading the system
• The heater is overheating
• There is a build-up of lime scale in the system 
• Too low water flow rate

How To Fix:

First off, inspect your Rheem tankless water heater for any leakage in the water & gas connections, pipelines, and pressure relief valve (if installed). Repair it with the help of a professional one.

Next, check for hard water mineral accumulation in the system to determine why your water heater may be leaking. Simply resolve it by flushing your tankless water heater. 

When done, ensure the correct water flow in the unit and adjust it to the recommended level. Typically, a gas tankless water heater needs 0.4 GPM to activate the burner. 

At times, a beep sound in the tankless water heater is a clear sign of the overloaded system. In such cases, try to reduce the hot water by closing some of the simultaneously running hot water faucets.

However, if your Rheem tankless water beeps after your efforts, I bet there would be a fault code in the remote display as with the beep sound. 

Don’t get in trouble! Let’s take a closer look at my Comprehensive guide on the heem water heater beeping to identify the exact issue. 

07. Rheem Tankless Water Heater Dripping Water

In general, there will be very less issues in the tankless model compared to tank ones, but dripping water from the bottom is the most common issue that users frequently face. 

Water leakage from the tankless water heater is a clear sign of serious damage to the system. It would be related to:

• High water pressure
• Malfunctioning of water pipes  due to freezing water
• Sediment build up
• Loose water pipe connection  
• Or, poor ventilation

How To fix:

Start by inspecting the water heater for any signs of damaged or worn-out parts. Tighten the loose connection or replace the worn-out ones. Next, check for high water pressure in the unit and adjust it to the recommended level. Make sure it is within 60 PSI- 80 PSI.

While struggling with the leaky Rheem tankless water heater at the base, inspect the water control & bypass valve for any damage. Water pipelines tend to leak or crack during freezing tempura. As a solution, thaw the pie to deal with the frozen pipes.

If needed, you’ll need to descale and flush out the tankless system. Finally, inspect the tankless water heater for poor ventilation and try to increase the airflow to the unit. 

For instance, we recommend you head to a professional installer to check out the venting system of your Rheem tankless water heater.

08. No power To The Remote

If there is no power to your Rheem tankless water heater remote control, be sure there is no loose or faulty wiring connection. It mostly happens when you try to hook the 2 remote control wires to the screws incorrectly. 

If that is not the case, the faulty remote or the defective PCB is the culprit that is failing to receive any signal.

Basically, the two screws on the lower left corner of the control board are designed to work on 120V AC (the main power to the unit). And the remote control requires 12V DC to run. 

In case you’re hooking the remote control wires with two of these two screws, it is quite obvious the element will be worn out. 

How To Fix:

Unhook the remote control wiring from the two screws and connect it directly to the unit. If the unit runs, just replace the bad wiring. Or, if needed, replace the bad remote control or PCB. 

To get detailed instructions, head over to our complete guide on Rheem tankless water heater remote control troubleshooting.

09. The Rheem Unit is Too Noisy

In general, tankless water heaters tend to work quietly. But it’s also not uncommon that the unit is making unusual noises while in operation. There would be several reasons to blame here for why your Rheem tankless water heater is making noise. 

The root reason is an accumulation of hard water minerals in the heater elements. During the heating process, the naturally occurring hard water mineral passes through the heater and settles down the elements. 

After long use, it turns into hard particles and starts creating a hissing or popping sound as the water heats up.

Another possible explanation is that any of the heater components are loose or not firmly attached. In that case, you will hear clattering or banging sounds while the heater is running.

How To Fix:

Fret not, as you’re not alone with this trouble when you’re struggling with your noisy heater. Here are the simple fixes to deal with the issue:

Step 01: Tighten The Loose Component

Inspect the system for any loose parts and secure them tightly in their place. If you’re uncomfortable doing this, we recommend seeking professional help.

Step 02: Flush Your Tankless Water Heater

If you’re suspecting of scale build-up in heater parts, be sure it is time to descale and flush your water heater. 

This is more likely related to turning off the power to the unit. Also, turn off the gas and water supply to the heater. Connect the hose to the unit’s flush valve and open the gas supply. Now, let the unit flush for several minutes.

Step 03: Check For Dirty Flow Sensor Or Inadequate ventilation

These are another two major reasons that can create a loud noise in tankless water heaters. Thus, inspect the water flow sensor and see whether it is in good working order. 

Clean it properly or, if needed, replace it with a new one. Besides, inspect the venting liens for any blockages and vacuum out the stuck debris using a vacuum cleaner.

Step 04: Check The Gas Pressure

If the noise results from a gas issue, you need to check the gas pressure of your Rheem gas tankless water heater to see if it is within the manufacturer’s recommended range. If needed, adjust the gas pressure. 

10. Rheem Tankless Water Heater Low Water Pressure

To be honest, it is frustrating to deal with the low water pressure of a tankless water heater. Look no further if you’re in the same row, as I’ve compiled an effective section here from long years of experience here.

Typically, the Rheem tankless water heater requires a minimum water pressure of 14 psi (97 kPa) and a minimum activation water flow rate of 0.4 gpm (1.5 lpm) to operate. 

If there is any malfunction, you’ll encounter several issues with the unit. Most highlighting, the system triggers fault code p1 on the Rheem control display.

However! Here is a short breakdown of all possible reasons for low water pressure with the possible solutions:

 11. Dirty Or Smelly Water

If you’re experiencing discolored water with an unpleasant odor from your water heater, don’t just assume that your Rheem unit is faulty. It can be an alarming sign of rust and sediment building up in the unit or in the water pipes of your house.  

Besides, the unpleasant odor would be the result of bacteria growth. The most common bad smell you may get from your unit is like “sulfur”, rotten eggs, decayed, or sewage-like scents. 

How To Fix:

Don’t just panic whenever you find Brown, yellow, or red water from your tankless water heater or if it smells like a rotten egg. Here, I am sharing some pro tips and tricks that I’ve applied on my own Rheem water heater and got the best results. 

Fix #1: As for the first step, you will need to flush your unit to remove sediment and rust buildup and improve the water quality. 

Fix #2: Secondly, if it’s quite frequent to build up rust in your home’s water pipes, you can easily remedy the problem by installing a water softener or water filtration system in your house. It will effectively reduce the hardness of the water.

Fix #3: Thirdly, to eliminate the bad odor from the water, it is enough to flush out the tankless system. Even to get better treatment, consider using a chlorine treatment and disinfecting the unit. 

For instance, we recommend you consult a professional and determine whether this treatment will be appropriate for your Rheem tankless water heater. 

12. Water Temperature Fluctuation  

It will be troublesome if you are using your Rheem tankless water heater, but the water temperature is continuously fluctuating. No! You’re not new here with this problem. 

Even the issue is more common in electric water heaters than gas water heaters. This is because the gas reaches the operating temperature almost immediately, but the electric heaters may take a few minutes to reach the required temperature.

Anyway, whatever the fact is. Here are the major reasons to blame for hot or cold water sandwiches in your Rheem water heater: 

• Improper temperature setting
• Improperly lengthened venting pipes
• Damaged flow sensor
• A dirty water filter on the cold water inlet
• Low water pressure 

How To Fix:

As for the first step, inspect the water filter connected to the cold water inlet of your water heater. Unscrew it from the connection and rinse it under running water. If needed, use a soft brush to remove debris or sediment.

Next, check the water flow sensor of your water heater and ensure it is in good working order. You need to replace the bad flow sensor. Besides this, make sure the venting lengths are installed according to the manufacturer’s instructions in the Rheem manual.

Check for plumbing crossover in your home water lines and fix it with the help of a professional plumber. As with all the above steps, adjusting temperature correctly is quite necessary to deal with the fact that the water temperature goes hot and then cold. 

Consult your owner’s manual to get clear instructions on how to do this.

13. Fan Continues To Rotate After The Hot Water Faucet Is Closed 

In case you’ve shut off the hot water faucets and still found that the fan is rotating in the tankless unit, be sure there is nothing to worry about. This is basically the post-purge cycle of the unit that is clearing the flue gases.

How To Fix:

As it is quite normal operating, you don’t require any troubleshooting actions here. 

14. Error Code Is Displayed 

Rheem tankless water heater has a built-in diagnostic system that is designed to display a fault code in the remote control whenever it triggers any issue in the system.

When you encounter an error code, all the operations from the tankless unit will just get stalled. That is the point, you’ll need to figure out the meaning of the appearing error and the responsive factors behind this.

Though there is a comprehensive list of the Rheem tankless heater error codes, here we’ve come up with a chart listing all the common Rheem fault codes along with the meanings and possible diagnostic procedures:

Seek Rheem Professional help

The problems listed above are just minor hiccups in the heater settings. Besides these, the best choices are the problems you encounter are more complex and beyond your repair. In most cases, the problem is more likely related to a damaged tankless water heater, indicating that it needs an upgrade.

But before that, it’ll be worth it if you contact your Rheem customer service for professional help. They will better help with your problems that are too complicated for you to try yourself.

When contacting Rheem customer support, you may ask for the following information:

• The model and serial number of your Rheem tankless water heater
• Address where the water heater is located
• Name and address of installation contractors and all qualified service companies that have worked on your water heater
• Original installation date.
• Details of the persisting problem
• Any previous history when you’ve tried to fix this problem by a service included with dates.

How To Maintain Rheem Tankless Water Heater To Extend The Lifespan?

A tankless water heater offers a cost-effective and energy-efficient way to produce hot water on demand. Still, the system requires proper maintenance to prevent premature component failure of the heater and ensure its optimal performance and longevity. 

Anyway, here are some pro tips to follow while performing maintenance on your Rheem tankless water heater:

01. Descale & Flush Your Water Heater Once Or Twice A Year

First up, you need to concentrate on regularly flushing your water heater. It effectively removes the sediment buildup or mineral buildup, clogging up the heater elements.

02. Freeze Protection 

Rheem tankless water heater equips with a freeze protection electric heater that prevents freezing inside the water heater down to an ambient temperature of approximately -30°F (-34°C). The heater protects the internal components of the water heater, and external piping and valves require additional freeze protection.

It is essential to drain the water heater before exposing it to the freezing temperature. This will protect the water heater, piping, and valves from freezing.

03. Vacation & Extended Shutdown

If you’re planning not to use your water heater e for an extended period of time, it is essential to turn off the power and water supply to your water heater.

04. Water Heater Inspection

It is recommended to inspect your water heater elements every six months for the accumulation of dust. For instance, clean out the burner chamber, blower motor, water filter, air intake filter, and venting lines.

How To Reset Rheem Tankless Water Heater?

Resetting the water heater is an effective process to diminish the existing problems and restart the unit. When it comes to resetting your Rheem tankless water heater, the first query starts with the location of the reset button.

Unfortunately, there is no built-in reset button in the Rheem tankless water heater. Yet, here are a few steps to follow to reset the unit.

Step #1: Turn off the power supply to your water heater. Also, unplug it from the power outlet.

Step #2:  Head over to the circuit breaker where your tankless water heater is connected. Flip the breaker to the Off position.

Step #3: Wait for about 5-10 minutes and let the heater reset at that time

Step #4: When done, flip the breaker switch back in the On position.

Step #5: Finally, restore the electric and water supply to your water heater.

FAQs:

Conclusion:

I’ve discussed how you can solve the most common issues with your water heater in this Rheem water heater troubleshooting guide. Hopefully, you’re facing a simple issue that won’t take too long to fix.

But if you’re unable to carry out any of the fixes, always take the help of an expert.