iHeat Tankless Water Heater Error Codes [How To Fixe]

Whenever the iHeat tankless water heater faces a problem with one of its components, it shows some error code on the monitor. These error codes help you understand specifically which part of the heater is malfunctioning. 

So, what do the iHeat Tankless water heater error codes mean? 

Different error codes of iHeat tankless water heaters have different reasons. For example, 

• E11: It means the resistance of the inlet temperature sensor is inconsistent.
• E21: It means, The resistance of the outlet temperature sensor is inconsistent.
• E32: This code means the water flow signal is disconnected.
• E52: This code indicates PCB failure. 

I have experience troubleshooting iHeat water heaters and it says different reasons require the repair or replacement of different parts of the heater. To know more about these codes, keep reading! 

iHeat Tankless Water Heater Error Codes

The good news is, that all the models of iHeat tankless water heater show similar error codes for similar problems. 

Those common models include iHeat electric tankless water heaters, AHS24D, AHS18D, AHS14D, AHS11D, AHS16D, AHS27D, and AHS21D. Also, the iHeat gas tankless water heater series AGL also shows these error codes. 

Here is a quick look at the reasons and solutions for each error code before we go into the detailed discussion. 

Here are some additional error codes you may face if you are a user of the iHeat Tankless water heater AHSD series. 

iHeat Tankless Water Heater Error Codes With Detailed Solutions

Here is an in-detailed discussion of what each of the error codes means on an iHeat tankless water heater. With my years of experience dealing with iHeat tankless water heaters, I have accumulated the solutions for getting rid of each of the codes. 

01. iHeat Error Code E11

The E11 error code in the iHeat tankless water heater indicates that the resistance of the inlet temperature sensor of this water heater is inconsistent. It usually happens when the inlet temperature sensor of the water heater is faulty. 

In this situation, the faulty sensor reads and sends the wrong signal to the PCB and as a result, the PCB provides inconsistent resistance in the inlet temperature sensor. 

How To Fix It: 

In this case, you need to replace the inlet temperature sensor to get rid of this problem. Here’s how to do it. 

Step 1: The first thing you need to do is, turn off the power supply to the water heater at the circuit breaker panel. And then, wait for the water heater to cool down if it has been running recently.

Step 2: Once the heater is safe to work with, Locate the existing inlet temperature sensor on the water heater. It’s located at the point where cold water enters the unit. It looks like a small cylindrical nut connected with a black wire. Before locating the sensor, you have to open the front cover of the heater. 

Step 3: After locating, carefully remove the wires connected to the existing temperature sensor. Make sure you remember how the sensor is connected to the inlet valve. 

Step 4: Unscrew the existing temperature sensor from its mounting point. Gently pull it out from its position.

Step 5: After that, insert the new inlet temperature sensor into the same mounting point as the old one. Make sure it’s securely in place.

Step 6: Attach the wires to the corresponding terminals on the new sensor, in the similar way the old one was connected. 

Step 7: Once the inept temperature sensor is connected, you can reattach the covering of the heater and power it on. 

02. iHeat Error Code E12

Error code E12 suggests that the inlet temperature sensor of the iHeat tankless water heater has been disconnected.

Sometimes, the wiring of the inlet temperature sensor can get detached from the inlet valve. As a result, the sensor can’t work and your water heater shows this error code. 

How To Fix It:  

Locate the inlet temperature sensor in the similar way mentioned above by following steps 1 to 2. After that, check the wiring of the sensor if it is properly connected. To be sure, you can remove the wiring and reconnect it. 

After that, close the front cover and turn on the power supply to the heater. The error code should be gone. 

03. iHeat Error Code E21

The E21 error code points to an issue with the outlet temperature sensor, where its resistance is inconsistent.

In this case, instead of the inlet temperature sensor, the outlet sensor sends the wrong information to the PCB.

How To Fix It: 

You have to replace the outlet temperature sensor of your iHeat tankless water heater. To replace the sensor, you have to follow the same procedure as replacing the inlet temperature sensor mentioned above. 

However, instead of the inlet sensor, you have to locate the outlet sensor which is found near the point from where the hot water flows out of the heater. 

04. iHeat Error Code E22

If you see the E22 error code, it means that the outlet temperature sensor of the iHeat tankless water heater is disconnected.

How To Fix It: 

To fix the E22 error code, first, you need to turn off the power to the heater and let it cool. After that open the front cover and locate the outlet temperature sensor from near the outlet water flow unit. Check if the wiring of the sensor is properly connected to the heater or not. 

To be extra sure, gently disconnect and connect the wiring again. Now you can install the front cover and power the heater to check if the error code is gone.

05. iHeat Error Code E31

E31 indicates a problem with water flow, either due to an interrupted signal from the water flow sensor or because of a lack of water flow.

How To Fix It: 

First, you need to check and make sure the water heater is getting proper water flow. The iHeat tankless water heaters require at least 1.5 liters of water flow per minute. 

Open a water source in your house, and check how much water you can get in a container within a minute. If you are getting less than 1.5 liters, consult your local plumber and fix the water supply. 

Sometimes the valve of the inlet pipe of your heater can be partially closed. As a result, you can get less water flow. Check the valve and make sure it is fully opened. 

If the water flow to the inlet pipe of the water heater is accurate, there must be a problem with the inlet flow sensor. In this case, you have to replace the water flow sensor of the water heater. 

Replacing the water flow sensor is almost similar to all tankless water heaters. So, the following video might help you with the process. 

06. iHeat Error Code E32

The E32 error code signifies that the signal from the water flow sensor is disconnected in the iHeat tankless water heater.

How To Fix It: 

The fixes for the error code E32 are similar to the fixes of the error code E31 mentioned above. So follow the same process and get rid of this error code.

07. iHeat Error Code E41

Error E41 suggests that the first heating element in the iHeat tankless water heater is faulty. The iHeat tankless water hearts have three elements. When there is any problem with the first heating element, you will see this code in the display. 

How To Fix It:  

Here are the things you have to do to get rid of this error code. 

1. Look at the wires connected to your iHeat tankless water heater. Make sure that they are properly connected and not disconnected or loose. Wires play an important role in transferring the electrical signal to the heating element.
2. Turn off the power to the water heater and remove the control panel to expose the water heater heating element. Now, Take a close look at the first heating element in the water heater. Make sure that it is firmly attached to the heater and the wirings are not disconnected. If they’re disconnected, the water won’t heat as it should, so you need to reconnect the wirings properly. 
3. Next, you have to check the triac. The triac is a part that controls the power sent to the heating element. Make sure it’s securely connected and not disconnected. 
4. Check that the waterway or inlet area where water flows through the heater is clear and unobstructed. If there are any blockages or restrictions in the waterway, you have to clean it properly so that water properly flows to the element.
5. If none of the above steps resolve the issue, you can now be sure that the heating element is faulty. Now you have to replace the first heating element in the way mentioned below.  

Step 1: First, make sure the power supply is turned off.

Step 2: After that, carefully disconnect the wires attached to the first heating element.

Step 3: Next, Unfasten and remove the faulty heating element.

Step 4: Replace it with a new one. Make sure the new heating element is compatible with your iHeat tankless water heater model. Try to buy the element from an authentic dealer. 

Step 5: After placing the element in its place, reattach the wires securely to the new heating element.

Step 6: Now, Turn the power supply back on and check if the issue is resolved.

08. iHeat Error Code E42

E42 points to a faulty second heating element within the iHeat tankless water heater. When the second or the middle heating element of your iHeat tankless water heater is particularly facing any problem, you will notice this code. 

How To Fix It: 

To fix this code, you have to follow all the things mentioned above under the error code E41 problem. But instead of focusing on the first element, you have to focus on the middle element. 

09. iHeat Error Code E43

The E43 error code indicates that the third or the last heating element of the iHeat tankless water heater is particularly faulty.

How To Fix It:  

The solution is similar to solving the error code E41 mentioned above. Follow the same procedure to get rid of this code. However, instead of handling the first heating element, for error code E43, handle the last or third heating element. 

10. iHeat Error Code E51

When you encounter the E51 error code, it means that the power control board (PCB) is not functioning despite the power being on.

How To Fix It: 

There is nothing much you can do about it on your own. Because when you get this error code, you must replace the PC board which is a very complicated task. All the sensors and connections need to be attached properly to the new PCB. 

So, it is highly recommended to call the iHeat dealer or a professional technician to replace the PCB. 

11. iHeat Error Code E52

Sadly, the error code E52 is also an indicator of a failure in the PC board (power control board) of the iHeat tankless water heater.

How To Fix It: 

You have to replace the PCB or the monitor in this case as well. As I have already mentioned, please consult your iHeat dealer for the PCB replacement. 

Also, suppose you have other codes instead of E51 and E52 and resolve the issues associated with that code. But still, you are getting these codes constantly. This also indicated that there is something wrong with either the PCB or the display of your iHeat water heater. In this case, you have to have these replaced as well. 

12. iHeat Error Code E60

The E60 error code refers to the overheat protection feature being triggered in the iHeat tankless water heater due to excessively high temperatures. The iHeat tankless water heater can get overheated for several reasons. Such as, 

1. Low water flow: It makes the heater overworked to supply the demand for hot water. 
2. Wrong power level: It makes the whole heating system inefficient and the unit gets hot easily. 
3. Faulty outlet temperature sensor: When this sensor is not working, the heater provides inconsistent water temperature which makes the system overworked. 

How To Fix It: 

To fix this error code, you have to do the following things. 

1. First, check the water flow and make sure it is at an accurate level which is at least 1.5 liters per minute. To ensure this, check for obstructions or blockages in the water lines or filters. Clear any debris that might be limiting water flow. Ensure that all water valves leading to the heater are fully open. If the problem still exists, consult a plumber. 
2. Check the owner manual of your iHeat tankless water heater for the required power level. Make sure your home power system is providing the appropriate level of power. Call an electrician if you need to adjust the power level. 
3. If you still get the error code, the outlet temperature sensor needs to be replaced. The process of replacing this sensor is already mentioned above. 

Additional Iheat Tankless Water Heater Error Codes For AHSD Series 

Apart from having those above-mentioned codes, if you are an AHSD series user, you can sometimes notice some additional codes as well. Here is the discussion on those codes. 

i) iHeat Error Code E1

The E1 error code indicates a faulty inlet temperature sensor in the iHeat tankless water heater. It means it’s not reading the incoming water temperature correctly.

How To Fix It: 

When you notice this code, you have to check the inlet temperature sensor. In other words, you have to troubleshoot all the problems regarding this sensor. 

That includes checking the connections and making sure the wires of the sensor are connected properly to the heater. This process is mentioned under the error code 12 problem. 

And if all the wirings are connected properly, you have to replace this sensor. This procedure is mentioned under error code E11. 

ii) iHeat Error Code E2

Error code E2 points to a faulty outlet temperature sensor in the iHeat tankless water heater. It indicates issues with accurately measuring the outgoing water temperature. 

How To Fix It: 

To get rid of this error code, you have to troubleshoot all the problems related to the outlet temperature sensor. Start with checking if the sensor is connected properly to the heater or not. You will find this procedure mentioned under error code E22. 

If the connection is proper, you have to replace the outlet temperature sensor. Follow the same procedure mentioned under error code 21. 

iii) iHeat Error Code E3

E3 suggests a problem with the water flow. It can be either due to a faulty water flow sensor or a lack of water flow, which can disrupt the heater’s operation.

How To Fix It: 

If this code appears in your heater monitor, you have to troubleshoot a number of things to get rid of this. This includes 

1. Interrupted water flow signal
2. Malfunctioning water flow sensor
3. lack of proper water flow

You will get the solutions to these problems mentioned above in this article under the E31 error code. 

If the error code doesn’t go away, that means the water flow signal is disconnected and you need to replace the water flow sensor. Follow the procedure mentioned under the error code E32 to replace this sensor. 

iv) iHeat Error Code E4

Error E4 signals a heating element failure in the iHeat tankless water heater. It means one of the 3  heating elements is not functioning correctly. More than one element can also be faulty in this case. 

How To Fix It: 

To get rid of the error code E4, you have to test the condition of all the heating elements of your iHeat tankless water heater one by one. 

Start with checking the first heating element, the procedure of which you will find under error code 41. Next, check the second heating element and repair it in the same manner mentioned above. 

Finally, check the third heating element in the same way I have mentioned above. 

v) iHeat Error Code E5

E5 indicates a faulty PCB control board in the iHeat tankless water heater. This PC board controls various functions of the unit.

How To Fix It: 

The only option to get rid of this E5 error code is to replace the PC control board. The consideration while replacing this device is mentioned earlier in this article. 

FAQs:

Conclusion 

Here goes the explanation of all the iHeat Tankless water heater error codes. I hope after reading this article those numbers on your heater monitor don’t feel strange anymore. When I first got these numbers on my heater, I got anxious as well. 

That’s all for today. Wish you all the best in solving your heater problem. Have a great day! 

If you are facing other issues with your iHeat water heater, you can read my article on – iHeat tankless water heater not heating.