Facing Rheem water heater gas valve problems can be extremely frustrating. When there are issues with the gas valve, it can mess up the gas supply and you may not get any hot water from your heater. I can tell you that from my own experience of working on numerous water heaters.
Luckily, I’ll cover everything you need to know to solve these issues in this guide. I’ll talk about:
- The main symptoms of gas valve issues.
- How to test the gas valve to make sure it’s bad.
- How to replace the gas control valve.
- How to reset the gas control valve.
You’ll be able to solve the gas valve issues after reading this guide. So, let’s dive in!
Table of Contents
Rheem Water Heater Gas Valve Problems [Common Symptoms]
When you see problems in your water heater, a faulty gas control thermostat can be the culprit in many cases. Here are the main warning signs of a bad gas control thermostat:
01. The Pilot Won’t Light Or Keeps Going Out
The first major sign of the gas control valve being faulty is the pilot light not coming on. When there are issues with the gas control valve, the gas may not flow to the pilot assembly. So, you won’t get any pilot light.
Similarly, the pilot may light on and off intermittently due to issues with the gas control thermostat. There are many other issues that can lead to this pilot light issue. And a defective gas control thermostat is one of them.
02. Too Hot Or Too Cold Water
The knob in the gas control thermostat is used to maintain the water temperature. But when you have a bad gas control valve, the sensors may not act properly.
So, the water temperature can be either very hot or very cold. The water being hot is particularly dangerous as it can cause scalding. On the other hand, the water being colder will be annoying when you’re in dire need of hot water. Sometimes, the temperature can also fluctuate.
You may also have no hot water at all. It could be the consequence of the pilot not lighting due to a faulty gas control thermostat.
03. Water Leaks
A leaking tank can also be the result of a bad gas control thermostat. When the gas control thermostat isn’t able to detect the water temperature, it can be overheated. Thus, the water can reach a temperature that’s too high.
It’s unsafe for the water temperature to be that much. So, the safety mechanism of the T&P relief valve could kick in here. It’ll get rid of some of the water through the discharge tube and you could end up with a water leak.
If you have frequent water leaks, that’s never a good sign. So, make sure to deal with the issue as soon as you can.
04. Gas Leaks
A faulty gas control thermostat can also lead to gas leaks. It’s also a serious issue but you’d be able to detect it most times due to the smell. You shouldn’t keep using the heater in this condition.
It’s ideal to turn off the gas supply to the heater, evacuate your house, and ask for help immediately in these situations. It’s better to be safe than sorry and you should be on the safe side to avoid any accidents.
How To Test A Rheem Gas Control Valve?
No matter how many warning signs point to a bad gas control valve, you can never be sure it’s actually bad until you test it. It’s also a bad idea to replace the gas control valve without being sure as it’s an expensive component.
So, you should test the gas control valve thoroughly to make sure that it’s actually bad. Now, when you see any of those symptoms mentioned above, it’s usually due to a bad gas control thermostat. But it can also be due to a bad thermopile. So, the first line of action here is to rule out the thermopile.
You’ll have to test the thermopile using a multimeter to make sure it’s good. If it’s good, then there’s a good chance that you have a bad gas control thermostat. For now, you can follow these steps to test the thermopile:
- Set up your multimeter to DC and send the range to millivolts.
- Remove the thermopile wiring connector from the gas control valve. You may have to rock the wiring harness back and forth at times to remove it.
- Attach the red lead of the multimeter to the red thermopile wire and the black lead to the black thermopile wire.
- Now, turn the gas control knob to the “Pilot” position and start lighting the pilot following the instructions in the manual.
- The reading in the multimeter should start going up as the pilot starts to light up. Hold down the gas control knob until the maximum voltage is achieved. It can take anywhere between 90 to 180 seconds.
Now that you have tested it, you have to collect the readings. Ideally, the reading should be within the range of 650 to 850 millivolts. A reading within that range indicates that you have a good thermopile.
If the reading is less than 400 millivolts, you can be sure that you have a bad thermopile. In that case, the gas control thermostat is not at fault and you’d have to replace the thermopile.
However, if the thermopile is within the acceptable range, you’re one step closer to concluding that you have a bad gas valve. The issue can be with the gas control thermostat, thermal switch, or temperature cut-off switch. Especially, if the pilot won’t stay lit even after the thermopile is good.
So, now you have to diagnose the gas control thermostat itself. Follow these steps carefully to inspect it and see if it’s faulty:
- Remove the screw at the bottom of the gas control thermostat that’s holding it in place.
- Press the two tabs on the top of the gas control valve using a flathead screwdriver. You should be able to pull out the front cover of the gas control thermostat at this stage. Be gentle while doing it and make sure you take off the front cover keeping it as square as possible.
- You’ll see three main pin connectors when you remove the thermostat cover. They are the common pin, the main burner pin, and the pilot pin. Here’s a picture to help you out:
- You have to measure the resistance between the different pins here. First, check the resistance between the common terminal and the pilot terminal. The red lead goes to the pilot pin and the black lead goes to the common pin.
- Similarly, measure the resistance between the common terminal and the main burner terminal. Collect the readings.
Now, it’s time to check the results. If you have a healthy gas control thermostat, both of these readings should be within 11 to 13 Ohms.
If the reading is outside this range, that means you have a bad gas control thermostat. Now, you know for sure that you have a bad gas valve. You’ll have to replace it.
How To Replace A Bad Rheem Gas Control Valve?
Unfortunately, there’s no way to repair a bad gas valve. If your gas valve is faulty, your only option is to replace it.
Your heater’s gas control valve can look a little different depending on the model of the heater you use. Here are the two common types of gas control valves in Rheem water heaters:
No matter which valve you have, the process of replacing it is pretty much the same. The main thing that’ll be different is the number of connections you’ll have to remove and reconnect.
With that said, it’s not difficult to replace the gas control thermostat on your own. You need the following tools to carry out the replacement job:
- New gas control thermostat.
- A garden hose.
- An adjustable wrench.
- A pipe wrench.
Once you’ve managed all of these tools, you can follow these steps to replace the gas control thermostat:
Step 01 – Shut Off The Gas & Cold Water Supply
Turn off the gas supply to the water heater. First, turn the gas control knob to the “Off” position. Then, shut off the main gas valve. The gas valve should be completely perpendicular to the gas lines when it’s turned off.
Next, shut off the cold water supply to the water heater. Open a hot water faucet to relieve some of the pressure inside the tank. You can keep the faucet open if you want the draining process to go a lot quicker.
Step 02 – Drain The Tank
You’ll need a garden hose to execute this step. Connect one end of the garden hose to the drain valve and place the other end where you want to get rid of the water. Open the drain plug and drain the water until the tank is empty.
Step 03 – Remove The Gas Valve Connections
There will be many gas valve connections that connect the gas valve to the other parts of the heater. You’d have to remove all those connections. The main connections here are the main gas line, the pilot tube, and the thermopile.
There’s also the gas tube that supplies gas to the main burner. You may have to remove even more connections based on your gas control thermostat. The adjustable wrench will come in handy here as you’ll need it to remove all the gas valve connections.
Step 04 – Remove The Old Gas Valve
Once you’ve isolated the gas valve from the other parts, you can safely proceed to remove it. You can close the drain valve now as it’s no longer needed. Use the pipe wrench and adjust its jaws as needed to get a good hold of the gas control thermostat.
Then, you’d have to rotate the gas valve counterclockwise. It’ll eventually become loose and you’ll be able to rotate it by hand. Keep rotating the gas valve and pull it out when it’s completely loose.
Step 05 – Install The New Gas Control Valve
Before putting the new gas control valve in, clean the threads of the tank. There could be sediment build up inside it. So, take a dry piece of cloth and get as much of the dirt as you can.
Then, apply Teflon tape to the threaded part of the new gas valve so that it makes a tight connection. It’ll also reduce the chances of any leaks in the future.
Once that’s done, you can install the new gas valve. Use the pipe wrench to rotate it clockwise until it’s secure in its place. Attach all the gas valve connections you removed.
Step 06 – Test For Leaks
The final thing to do in order to complete the installation is to test for leaks. Once you’ve tightened the connections, fill the tank with water. If there are any water leaks, you haven’t installed the heater correctly. In that case, you need to go to the previous steps and do them right.
Then, turn on the gas supply and try to light the pilot. Apply some soapy water to the gas connections. If there’s any gas leak, air bubbles will form. It also means that a mistake was made during the installation. You’d have to tighten the gas connection that’s leaking.
But if there are no leaks, then you have done a good job installing the thermostat. Hopefully, you’ll no longer have any issues with your gas control thermostat and get adequate hot water from your heater.
How To Reset A Rheem Gas Control Valve?
Resetting the Rheem gas control valve is an easy job. It’s a good idea to reset the gas control valve after a new installation or when you want to clear error codes. Here are the steps to do it:
- Turn off the gas control valve and unplug the heater from the power outlet.
- Wait for a couple of minutes.
- Plug the heater back in and turn the valve back on.
- Now, comes the important part. You’d have to do the next step within 30 seconds. So, pay close attention.
- Turn the gas control knob from the “Low” to the “Hot” position seven times within this 30 seconds period.
That’s all you have to do to reset the gas control valve in your Rheem gas water heater. If there were any error codes flashing, they should go away by now. Once you’ve done that, you can set the heater to your desired temperature and enjoy the hot water from it.
FAQs:
When do you get hotter water than the gas control thermostat settings?
If sediment has accumulated on the gas control thermostats, they can get the wrong readings. Hence, you’ll get hotter water at the faucet. Drain a few quarts of water from the tank every month to prevent this issue.
What is the main purpose of the gas control thermostat?
Users of the heater can regulate the water temperature using the gas control thermostat. They can set the thermostat to their desired water temperature. That’s the primary job of the thermostat.
Are there any safety devices in the gas control thermostat?
There are two safety devices in a gas control thermostat. The first one is designed to shut off the gas supply to the main burner when it’s extinguished. The second one also shuts off the gas supply to the burner when the water temperature is too high.
What is a safe temperature to set using the gas control thermostat?
It’s a great idea to set the water temperature at 120°F or lower to be absolutely safe. There’s very little risk of scalding even for children and elders if the water is set at that temperature.
Conclusion
Now, you know the main reasons behind Rheem water heater gas valve problems and how you can fix them. You have to proceed serially to test the thermostat first. Then, you have to replace it if it turns out to be faulty.
You can always take the help of a qualified technician if you don’t feel like replacing the thermostat yourself. Check out my Rheem gas heater troubleshooting guide if you’re facing other issues with your heater.
Also read “How to fix Rheem water heater 2 flashing“.