iHeat Tankless Water Heater Troubleshooting Guide

When I started repairing water heaters, I was surprised that users of well-established brands like iHeat also share their concerns frequently. So, Having a tankless water heater from a renowned brand doesn’t mean you won’t face problems from time to time.

 So, what is the iHeat Tankless Water Heater Troubleshooting process? 

To troubleshoot your iHeat tankless water heater, first, you need to identify common problems it shows. From my years of experience with this brand, I found the following problems to be the most common. 

• The Water Heater Won’t Turn On: You need to ensure proper power supply and attach wires properly. 
• The Heater Is Not Hot Enough: Adjust the temperature, water flow, and cold water mixing. 
• The Heater’s Actual Temperature Is Less Than The Setting: Adjust the voltage and compensate for the anti-scald feature. 

There are more problems and the solutions also need a detailed discussion if you want to understand them properly. So, keep reading! 

IHeat Tankless Water Heater Troubleshooting

Before going into the detailed discussion, here’s a blue map of the article. I have troubleshooted several models of iHeat tankless water heaters and luckily, all models show almost similar kinds of problems for similar reasons. 

So, whatever model you are using, this troubleshooting guide will help you. These models include the iHeat tankless water heater S series, AHS series, AHSH series, AHSD series, and HS series. 

However, the iHeat gas tankless water heaters or the AGL series have some unique problems that happen only in gas heaters. Their troubleshooting is also different. I have incorporated those solutions in this article as well. 

Now, without any further ado, let’s jump into troubleshooting. 

General iHeat Tankless Water Heater Problems Troubleshooting

Here are some general problems you might encounter every then and now with your iHeat tankless water heater. 

Problem 1: IHeat Tankless Water Heater Won’t Turn On

Sometimes, you may have a problem with your iHeat tankless water heater where you attempt to start your tankless water heater, it simply does not respond or activate. This can be quite frustrating.

Reasons: 

There can be several reasons behind this problem. Here are those. 

• Lack of power to the unit: If there is a lack of power reaching the tankless water heater, it won’t start. This can occur if the circuit breaker or fuse connected to the heater is switched off or has tripped, or you haven’t turned on the heater. 
• Loose wiring connection: A loose wiring connection can disrupt the electrical flow to the iHeat tankless water heater. As a result, the heater will refuse to start. 
• Worn-out thermostat: The thermostat in a tankless water heater is responsible for regulating the temperature of the water. If the thermostat becomes worn out or malfunctions, it can send incorrect signals to the heating elements. This can result in the heater not turning on.

How To Fix It: 

To fix this problem, you have to follow the below-mentioned troubleshooting tips. 

Step 01: Check Power Supply

Make sure that there is power reaching the unit. Check if the circuit breaker or fuse connected to the heater is switched on. If it has tripped, reset it and try turning on the heater again.

Also, make sure you have turned on the heater using the power button.

Step 02: Inspect Wiring Connections

1. First, turn off the power to the water heater at the breaker/fuse box to ensure safety.
2. Carefully inspect all the wiring connections on the tankless water heater. Look for loose or disconnected wires.
3. If you find any loose connections, tighten them securely. Make sure to follow proper electrical safety procedures.

Step 03: Test the Thermostat

If the above solutions don’t work, you have to test the thermostat and if required, you may need to replace the thermostat. The testing and replacement process of the thermostat is very complicated. So, it is best for you to leave this job for a professional electrician. 

Problem 2: IHeat Tankless Water Heater Is Not Hot Enough 

In this case, the water heater seems to be running, but the hot water it produces isn’t as warm as you would expect or desire.

Reasons: 

If you feel that your water heater is not supplying enough hot water as it should, the following reasons can be behind it. 

• Low-Temperature settings: If you’ve set it too low, the hot water coming out won’t be as hot as you might want.
• Very high water flow rate: If the cold water flowing through the heater has a high flow rate, the heater won’t be able to cope up with the supply. As a result, it will fail to properly heat the water. 
• Low voltage than required: iHeat tankless water heaters need a certain amount of electrical voltage to work correctly, depending on the model. If the voltage supplied to the heater is lower than what it needs, it might not be able to heat the water adequately. It will lead to insufficient hot water.
• Excessive cold water mixing: Sometimes, the heater works fine, but if a lot of cold water is mixed in with the hot water, it can dilute the hot water and make it less hot when it comes out of the tap or shower head. So, even if the heater is doing its job, mixing too much cold water can make it seem like it’s not heating enough.
• Crossed wiring connection: During installation of the heater, If the wires are connected incorrectly, the heater may not work as intended. And this can affect its ability to heat water to the right temperature.
• High Altitude: if you are using a gas iHeat tankless water heater and you’re using the unit at a very high elevation, like above 6,000 feet, it might not heat the water properly.
• Cracked Flame Regulator: Again, if you are using a gas water heater, look through the teardrop-shaped windows on the front cover of the unit. If you see a blue flame, that’s good. But if the flame is yellow, it means there’s a problem with the gas regulator, possibly a crack in it.

How To Fix It:

To fix your iHeat tankless water heater not enough hot water problem, follow these troubleshooting steps. 

Step 01: Adjust the Temperature

Increase the temperature setting on your tankless water heater to the desired level. Be cautious not to set it too high, as this can lead to scalding water. The ideal temperature for a tankless water heater is 120 degrees Fahrenheit. But make sure, you don’t go above 140 degrees.

Step 02: Adjust the Water Flow

Check the faucet of your house for the water flow. If the water flow seems to be too high, you need to reduce the water flowing to the inlet valve of your heater. Partially close the inlet valve of your water heater to adjust the flow rate. 

Step 03: Ensure Proper Voltage

Different series of iHeat tankless water heaters operate at different voltages. If your home voltage does not match the required voltage, the heating element of the heater won’t be properly heating the water. 

Check your owner’s manual for recommended voltage and adjust it with your home electric supply with the help of an electrician. 

Step 04: Adjust Cold Water Mixing

Adjust the mixing valve or faucet to reduce the amount of cold water mixed with the hot water. This will help maintain the desired hot water temperature when it reaches your taps or shower heads.

Step 05: Have the wiring Checked

If none of the above solutions works and you have recently installed the heater, there must be a connection problem. Call the same plumber who installed the heater and have the wiring checked. Make sure the wiring is connected properly this time. 

Step 06: Install the heater in the correct Altitude

Make sure the water heater is installed below elevations of 5,500-6,000 feet. If it’s installed above this range, you should call the dealer or a professional plumber to reinstall the heater within optimal altitude. 

Step 07: Repair Cracked Regulator 

If you are sure that you have a cracked regulator in your iHeat tankless water heater, stop using the heater immediately. Turn off the power to the heater as it can be dangerous. Also, do not attempt to repair this by yourself. 

You should immediately call the manufacturers of iHeat (American Heat) directly and notify them about the problem. 

Problem 3: The Heater’s Actual Temperature Is Less Than The Temperature Setting

In this problem,  even though you’ve set a specific temperature for your tankless water heater, the water it delivers does not reach that temperature and remains cooler.

Reasons: 

There are several reasons why your heater’s actual water temperature doesn’t match the temperature of the thermostat. Let’s discuss: 

• Low Voltage: When there’s not enough electrical voltage reaching the water heater, it will struggle to heat the water to the desired temperature. For example, the iHeat AHS series requires 240 volts. If you provide only 120 volts, the system won’t run to its fullest potential. 
• Activated anti-scald feature: Many water heaters have a safety feature that prevents water from getting too hot to protect you from burns. If this feature is activated, it can limit how hot the water can get, even if you set it to a higher temperature.
• Long pipe thermal loss: If the hot water has to travel through long pipes to reach your faucet or shower, it can lose heat along the way. So, by the time it comes out, it might not be as hot as you want it to be.

How To Fix It: 

Here are the ways to fix this problem. 

Step 01: Adjusting the Voltage

Make sure that your water heater is getting the right amount of electrical power. For example, if your iHeat AHS series needs 240 volts, make sure it’s receiving that amount.

If your home electric supply can’t provide the right amount of power, you need to consult an electrician to check your electrical connections.

Step 02: Compensating the Anti-Scald Feature

If your water heater has an anti-scald feature that prevents the water from getting hot enough, you can adjust this setting. You can completely turn off the supply of cold water to get the perfect amount of hot water. Then you can mix cold water manually as per your preference. 

Another way around this feature is to increase the water heater temperature slightly more than you intended to get. This will help you get hotter water. 

Step 03: Compensating Long Pipe Thermal loss

It is completely normal to get less hot water if your faucet is far away from the heater. You can fix this problem by increasing the temperature of the water heater.

Problem 4: IHeat Tankless Water Heater Not Heating

This issue means that the tankless water heater is failing to effectively heat the water. It leaves you with unheated or lukewarm water when you need hot water for showering or doing the dishes.

Reasons: 

Here are the reasons behind the iHeat water heater not heating problem. 

• Lack Of Power: If the water heater doesn’t have enough electrical power, it won’t work properly.
• Inadequate Water Pressure: The iHeat electric water heater and gas water heaters require a water flow rate of 0.25 gallons. If your water supply doesn’t have this force, the system won’t activate even though the inlet water is flowing. And it will result in no hot water. 
• Incorrect Voltage Supply: As mentioned above, all iHeat tankless water heaters require a specific voltage to heat water. If they don’t have enough voltage, the elements won’t heat water. 
• Disconnected Inlet/Outlet Pipe: The water heater relies on connected pipes to bring in and send out water. If these pipes are disconnected or blocked, the heater won’t function correctly.
• Inadequate Gas Supply: This is the reason for an iHeat gas water heater not heating problem. If there’s not enough gas flowing to the heater, it can’t heat water effectively.
• Worn-Out Battery: If you have a gas tankless water heater by iHeat, old batteries can be a reason why you are not getting hot water. 
• Malfunctioning Internal Parts: When any of the internal parts of the heater is faulty, it will cause the heater not to heat water. 

How To Fix It: 

If you want to get rid of this not heating problem, try the following troubleshooting method. 

Step 01: Ensure Proper Power 

Check the circuit breaker or fuse connected to it. If it’s switched off or tripped, turn it back on. Make sure you’ve turned on the heater too.

Step 02: Provide Proper Water Pressure

Make sure that your water supply has enough force. If it doesn’t meet the required flow rate or pressure, consult a plumber to improve your water system.

Step 03: Provide Proper Voltage 

Confirm that your water heater is receiving the correct voltage. If not, consult an electrician to know what to do and ensure it gets the right voltage.

Step 04: Check Inlet/Outlet Pipe

Check that all pipes connected to your water heater are properly attached and not blocked. Reconnect or clear any obstructions to ensure water flows correctly.

Step 05: Provide a Proper Gas Supply

If you are using a gas water heater, ensure there’s enough gas supply. Contact a gas technician to check and improve the gas flow.

Step 06: Replace the Batteries 

If you have a gas water heater with a battery, replace the old batteries with fresh ones. This should help the heater function properly. Make sure the batteries are compatible with the heater. 

Step 07: Repair Internal Parts

If none of the above-mentioned troubleshooting steps work, and if you suspect internal parts are faulty, it’s best to call a professional technician. They can diagnose and replace any malfunctioning parts.

Additional Troubleshooting For IHeat Tankless Water Heater AGL Series

Problem 1: IHeat Tankless Water Heater No Audible Clicks At Startup

When you encounter this issue, you do not hear the usual clicking sound that indicates the normal startup of the heater. This means the heater is not turning on and you also don’t hear the ignition sound. 

Reasons: 

After repairing several iHeat gas water heaters, I have found the following reasons for this problem. 

• Dead or incorrectly installed batteries: If the batteries in the heater are dead or not put in the right way, the heater’s ignition won’t work. As a result, your heater will not start and you won’t hear the usual clicking sound. 
• Reversed Incoming and outgoing water connections: The heater needs water to operate, but if the hot and cold water pipes are mixed up, it can confuse the system. This confusion can prevent the heater from starting up correctly, and you won’t hear the usual clicks.
• Insufficient water pressure: iHeat gas tankless water heaters require a certain amount of water pressure to work effectively which is at least 20 PSI. If the water pressure is too low, it might not trigger the heater to start, and you won’t hear any clicks. 
• Stuck water regulator: Sometimes, the water regulator of the heater can get stuck by epoxy or other debris. That restrains enough water to pass which is needed to start the system. 
• Disconnected wire inside the unit during shipping: Sometimes, wires inside the heater can come loose or get disconnected during shipping or handling. When the internal wires are not properly connected, it can prevent the heater from starting.

How To Fix It:

When I encounter an iHeat gas tankless water heater with this problem, I usually perform the troubleshooting process mentioned below. And for me, it worked every time. 

Step 01: Change the Batteries

Replace the batteries with fresh ones, making sure to put them in the correct way. 

Check and correct the water connections

Swap the hot and cold water pipes to ensure they are correctly connected. The hot water should be connected to the hot water inlet and the cold water to the cold water inlet.

Step 02: Provide Sufficient Water Pressure

Increase the water pressure to at least 20 PSI. You can do this by adjusting the water pressure regulator or checking for any obstructions or leaks in the water supply line.

Step 03: Clean the water Regulator 

If the water regulator is stuck, you will need to clean or replace it. Remove any debris or epoxy that may be blocking it. If it’s damaged beyond repair, consider getting a replacement regulator and installing it correctly.

Step 04: Check The Wiring Connections

Open up the heater’s access panel carefully and check for any loose or disconnected wires. If you find any wires are disconnected, reconnect them properly. Always make sure to turn off the gas supply to the heater before performing this. 

And it’s better to call a professional for this job.  Because manufacturers of iHeat are strictly prohibited from even removing the cover without their consultation. So, call their technical support at 888-818-4328 and they will tell you what to do. 

Problem 2: IHeat Tankless Water Heater Keeps Turning Off

When your tankless water heater keeps shutting down on its own at irregular intervals, despite your attempts to keep it running, it can be frustrating and inconvenient.

Reasons: 

If your iHeat water heater keeps turning off every time you turn it on, the following reasons need to be considered. 

• Inadequate Water Flow and Low Pressure: iHeat tankless water heaters require a certain minimum
• flow rate of 0.25 gallons and water pressure of 20 PSI to operate effectively.
• High Wind: Strong winds can disrupt the combustion process in your iHeat tankless water heater. They can affect the proper ventilation and combustion air supply. It leads to an unstable flame or extinguishing it altogether. This can result in the water heater turning off frequently. 
• Gas Supply Issues: If your gas tank is empty or almost empty, it might have some air mixed with the propane gas. This can happen, especially with new tanks when they are filled for the first time. This contaminated gas can cause the heater to keep shutting down. 
• Misaligned or Bent Ignition Sensors: If one of the ignition sensors is bent or too close to the burner, the sensor gets hot easily. For the safety of the heater, the sensor shuts down the system to prevent any fire hazards. 
• Incorrect Thermocouple Placement: When the thermocouple is positioned either too high or too low, it cannot sense the pilot flame. As a result, it will not generate the necessary electrical signal to keep the gas valve open. This leads the gas supply to the system being shut off frequently. 
• Loose or Disconnected Gas Sensor Wire: If the gas sensor of your iHeat tankless water heater comes loose, it can cause the system to shut off frequently. 

How To Fix It: 

If your unit starts and then shuts off, here are the troubleshooting processes you need to follow: 

Step 01: Provide Adequate Water Flow And Pressure

You have to ensure that the water flow rate is at least 0.25 gallons per minute. Also, check that the water pressure is at least 20 PSI. You can clean the clogged filters or screens in your water supply line to increase the water pressure. 

Step 02: Safeguard The Burner From Wind

Shield your tankless water heater from strong winds by using barriers or covers. Ensure proper ventilation and airflow around the heater to minimize wind interference.

Step 03: Provide A Proper Gas Supply 

Turn your water heater on and off a few times using the shower head switch (do this about 5 times). This will help remove the air from the gas and should make your water heater work properly again. Also, make sure the gas tank has enough propane in it. 

Step 04: Repair The Ignition Sensor

Check to make sure the ignition pins and the heat sensor are standing upright like the letter ‘L’ and pointing straight to the back of the box. If they are not straight (for example, if they are at a 45-degree angle), you can use pliers to carefully straighten them. If you need help with this, please call technical support at 888-818-4328.

Step 05: Adjust The Thermocouple Placement

Make sure the thermocouple is at the same level as the hole in the heat exchanger. If it’s not aligned correctly, you must call the technical support of iHeat for help.

Step 06: Connect Gas Sensor Wiring Properly

Check the gas sensor wire for any loose or disconnected connections. Reconnect any loose wires securely to ensure proper functioning. However, it is recommended to call technical support to fix this issue rather than handle it yourself if you don’t have enough experience with the heater.  

Problem 3: IHeat Tankless Water Heater Does Nothing 

This problem indicates that when you attempt to operate or activate the heater, it remains entirely unresponsive. And it doesn’t perform any actions or functions it’s supposed to.

Reasons: 

If your iHeat gas tankless water heater does nothing, there can be several reasons for that. Let’s have a look at them. 

• Wrong inlet/outlet connections: In an iHeat gas tankless water heater, there are specific connections for the water inlet and the water outlet). If these connections are set up incorrectly, the water heater won’t start and will not do anything at all because it’s not receiving water through the proper channels.
• Lack of propane supply: If there is no or insufficient propane supply, the heater cannot generate the heat needed to warm the water.
• Dead batteries: If the batteries are dead or low on power, the heater won’t have the necessary electrical energy to start or ignite the burner. This can lead to the heater appearing unresponsive.

How To Fix It: 

If you want your water heater to respond properly, here are the troubleshooting processes you need to follow. 

Step 01: Properly Attach The Water Connection

Make sure that you’ve connected your cold water source to the right side of the system, which is the far-right connection. Also, ensure that the shower handle is connected to the water outlet side. 

Step 02: Refill Propane Cylinder 

Make sure you have enough propane gas available for the system to operate. Running out of gas can cause the system to stop working.

Step 03: Replace Batteries 

Make sure that you have fresh batteries in the system. Also, make sure the batteries are connected in the right direction and are compatible with the heater. 

IHeat Tankless Water Heater Error Codes

Apart from the problems mentioned above you may sometimes notice some error codes in your iHeat tankless water heater. These codes are messages from the heater when any of its components fail to perform efficiently. You need to know these codes to resolve the issue.

Luckily the codes are similar for all models of iHeat tankless water heater. So, here they are. 

Now, let’s discuss these codes in detail

Error Code E11

If you are seeing error code E11, it means that the inlet temperature sensor of your tankless water heater exhibits irregular resistance. To address the issue, you should replace the defective inlet temperature sensor in your tankless water heater.

Error Code E12

Error code E12 indicates that the inlet temperature sensor is not properly connected to your tankless water heater. Make sure to properly reattach the sensor to ensure it functions correctly.

Error Code E21

When error code E21 appears, it points to an issue with the outlet temperature sensor, which shows inconsistent resistance. If you’re facing problems with the sensor, I will advise you to replace the problematic sensor.

Error Code E22

E22 suggests that the outlet temperature sensor in your tankless water heater is not connected as it should be. Make sure that you reattach the sensor correctly to avoid further issues.

Error Code E31

If error code E31 is displayed, it signifies a problem with the water flow signal, possibly due to a malfunctioning water flow sensor. To resolve the problem, first, confirm that there is adequate water flow, and if needed, consider replacing the water flow sensor.

Error Code E32

E32 indicates that there is no water flow detected in your tankless water heater, which could lead to operational problems. If the water flow sensor is found to be malfunctioning, it is necessary to install a new one.

Error Code E41

When you encounter error code E41, the first heating element in your tankless water heater is not functioning correctly. You should fix or replace it as required.

Error Code E42

Error code E42 points to a problem with the second heating element, which is not operating as it should in your tankless water heater. Address the issue by fixing or replacing the second heating element as needed.

Error Code E43

E43 suggests that the third heating element in your tankless water heater is not performing as expected. If the third heating element in your tankless water heater is not working properly, take steps to fix or replace it.

Error Code E51

If you see error code E51, it indicates that the PCB in your tankless water heater is not functioning despite the power being on. To rectify the situation, install a new PCB in your tankless water heater.

Error Code E52

E52 error code signifies a malfunction of the PC board in your tankless water heater. In case of PCB malfunction, you may need to install a new one to ensure proper functionality.

Error Code E60

Error code E60 is displayed when the overheat protection mechanism is activated in your tankless water heater, indicating a potential overheating issue. In this case, reset either the water flow level or power level to the appropriate settings to resolve the issue with your tankless water heater.

If you are a user of the iHeat tankless water heater AHSD series, you may notice some other codes as well. Such as: 

• Error Code E1: Repair or replace the inlet temperature sensor.
• Error Code E2: Repair or replace the outlet temperature sensor.
• Error Code E3: Make sure the heater is getting proper water flow. If needed, replace the water flow sensor. 
• Error Code E4: Test all three heating elements and repair or replace them as needed. 
• Error Code E5: Repair or replace the PCB. 

iHeat Tankless Water Heater Maintenance

If you compare traditional water heaters with tanks, tankless water heaters require less attention and fewer replacement parts. However, to ensure they work well and last a long time, it’s essential to do some regular maintenance. Regular maintenance will save you from performing troubleshooting more frequently. 

Here are some common maintenance for iHeat tankless water heaters. 

Clean or Replace the Water Line Filter

Some IHeat tankless water heaters come with a filter in the water line. This filter catches stuff like minerals from hard water and tiny particles. If these things pile up, they can cause trouble not just for your water heater but also for your plumbing and gadgets.

Certain filters can be cleaned and used again, but others must be swapped with new ones. Look in your user manual to see what to do. If your water heater doesn’t have a filter already, you can put one in to make your water cleaner.

01. Clean the Air Filter

Some tankless water heaters made by IHeat, like the AGH series, use natural gas to work. These heaters have a filter in a specific spot, like a barrier, between the pipe that brings in air and a fan that helps the heater run. Over time, this filter can get filled with dust and dirt, which can mess up how the air flows.

When this happens, you might notice problems with the electricity that powers the heater. Fixing this issue is usually not too hard. You need to take off a few screws, remove the filter, wash it with water to get rid of the dirt, let it dry, and then put it back where it belongs.

02. Descale and Flush the System

The most complex part of tankless water heater maintenance is descaling and flushing the heater. Even with a water filter, minerals like lime and calcium build up inside the tankless heater over time.

If you have hard water, you should try to descale and flush the unit about once a year. For those with soft water or a water softener system, this procedure can be done every 3-5 years.

To remove the mineral deposits, you can use either white vinegar or any specialized descaling solutions for the water heater. Take a submersible pump and circulate the vinegar through the tankless water heater for around 45 minutes. After descaling, you’ll need to flush the unit with clean water. You can do this by connecting a garden hose to the hot water side service valve.

FAQs:

Conclusion

That’s all about iHeat Tankless Water Heater Troubleshooting. First of all, thank you for reading this article through to the end. I hope by sharing my experience, I could help you with your water heater. 

Still, if you are not very comfortable with plumbing and electrical devices, it’s best to leave this jot for professionals. 

That’s all. Be safe and have a great day!

Note: You can also read our Camplux Water heater troubleshooting guide.