Rheem Tankless Water Heater Error Code 61

Rheem Tankless Water Heater Error Code 61 means combustion fan failure or indicates the blower motor is at fault. This error code will pop up on the controller display due to one of the following reasons: 

• The combustion fan doesn’t spin freely
• Flue blockage
• Ventilation issue
• The wiring harness to the fan motor comes loose
• Molex connections of PCB get damaged
• Ignition issue
• Defective control board

To reset the error code, resolve those issues. I will walk you through each troubleshooting step to fix the error code 61. So, let’s dive in. 

How To Fix Rheem Tankless Water Heater Error Code 61?

Here is a table summarizing the key information on how to fix Rheem Tankless Water Heater Error Code 61:

Issue	Cause	How To Fix
Combustion fan doesn’t spin freely	Blockage in fan assembly, defective blower motor	1. Check fan assembly for obstructions, remove if found.2. Test blower motor voltage, replace motor if needed
Flue blockage	Restricted vent pipe	Inspect and clean flue vent to remove blockage
Ventilation system issue	Improper installation	Verify installation per manual, call technician if needed
Wiring harness loose	Damage to wiring harness	Secure wiring harness, replace if damaged
Molex connectors damaged	Loose or damaged connectors	Tighten/replace Molex connectors on control board
Ignition system issue	Defective igniter	Refer to guidelines for error code 11
Defective control board	Faulty control board or circuits	Test control board voltage, replace if faulty

1. Combustion Fan Doesn’t Spin Freely 

The combustion fan is responsible for supplying air for the combustion process. If the fan doesn’t spin freely, it will fail to deliver air to the combustion chamber for proper combustion. Generally, a blockage in the combustion fan assembly or a defective blower motor will cause the combustion fan to fail. 

How To Fix: 

First, check the fan assembly for obstructions. If you find any, remove the blockage. 

Second, inspect the blower motor electrically. Regarding this, turn off the unit by pressing the power button on the remote control. Then, unplug the power cord of the unit. Apart from this, close the water supply valves and gas shut-off valve.  

Afterward, unscrew the front access panel. Plug the power cord into the outlet and turn on the unit by pressing the power button on the remote control.

Next, get a multimeter and set the voltage meter to read between 12 and 18 DCV. 

For indoor models, place the meter leads between the black and white wires. On the other hand, you should place the leads between the blue and red wires for outdoor models. 

Now, let’s turn on the blower motor. To activate the blower motor, you must press and hold the Max button. It’s located on the upper right side of the control board. There are three buttons. You should press the middle one.

If you get a voltage reading between 12 and 18 DCV, understand the blower motor is working. 

Now, release the max button. 

For the final test on the blower motor, set the voltage meter to read between 4 and 10 DCV. Again, place the leads between the black and blue wires for indoor models. Otherwise, you should place the leads between the blue and yellow wires for outdoor models. 

This time, press and hold the max button again to activate the blower motor. If you get a voltage reading between 4 and 10 DC volts, understand the blower motor is functional. 

If not, you should replace the blower motor to operate the combustion fan properly. I recommend you call a certified plumber to replace the blower fan. 

2. Flue Blockage

A blockage in the flue vent can affect the proper ventilation and lead to error code 61. Due to a restricted vent, the water heater won’t draw enough air for proper combustion. So, inspect the flue vent and ensure there is no blockage. If needed, clean the vent pipe to remove the nest or other stuff. 

3. Ventilation System Issue

Let’s talk about why the ventilation system is so crucial. Imagine a scenario where your tankless water heater encounters hiccups in its ventilation. It’s not just about letting out a sigh of frustration; it could trigger error codes related to combustion. When you fail to install the venting system according to the manual, you will experience a combustion issue with your water heater.  

How To Fix: 

Here’s a friendly nudge to consider: give your tankless water heater the breathing space it deserves. A well-maintained ventilation system ensures that your heater operates smoothly, efficiently, and without those pesky combustion-related error codes like fault code 61. It’s the secret sauce to unlocking the full potential of your appliance. I recommend you check the user manual here to verify you vent the unit correctly. Or, you can call a certified technician to check the venting and let them correct if required. 

4. Wiring Harness to the Fan Motor Comes Loose

Follow the wiring harness from the control board to the fan motor. If the wiring harness comes loose or gets damaged, the fan motor won’t get the juice it requires to spin. As a result, the unit will beep the error code 61 on the controller display to seek your attention. To reset the error code, ensure the wiring harness to the fan motor is secure & tight. If required, replace the wiring harness. 

5. Molex Connections Of PCB Get Damaged

Inspect the Molex connections on the control board. If the Molex connectors come loose, you will get no signal on your control board. In this case, tighten the Molex connections or replace them if required. 

6. Issue with Ignition System

The ignition system plays a vital role in the combustion process. Malfunctions in the ignition system, like a defective igniter, will affect the combustion process. And the error code 61 is the result you get due to the ignition system problems. 

Fortunately, I published an article on Rheem Tankless Water Heater Code 11. In that article, I described everything related to the ignition issue. Check out the guideline and resolve the issue with the ignition system. 

7. Defective Control Board

The control board is like a human brain. It diligently keeps an eye on all the moving parts, ensuring everything dances to the right tune for that perfect, uninterrupted flow of hot water. But the heck is- a glitch in the control board or its trusty circuits can throw a little hiccup into this well-choreographed performance.

How To Fix: 

You must replace the control board if it’s at fault. However, go along with these steps to inspect the control board electrically: 

• Turn off the water heater and unplug the power cord from the wall outlet. If you have Rheem outdoor models, turn off the unit at the breakers. 
• Unscrew the access panel. 
• Locate the water and gas supply valves at the bottom of the unit and turn them to the Off position. 
• With the front cover removed, restore the power to your water heater. Then, turn the unit on by pressing the power button. 
• Locate the Molex connector G. This connection has red, black, white, yellow, and blue. 
• Set the multimeter to read between 144 and 192 DCV. For an indoor model, place the leads between the black and red wires. Otherwise, position the leads between the blue and white wires. 
• If you get a voltage reading between 144 and 192 DCV, understand the control board is at fault. Otherwise, you should replace this component. 

I recommend you call a certified plumber to replace the control board if it’s at fault. 

How Do I Reset Rheem Tankless Water Heater?

Follow these simple steps to reset your Rheem Tankless Water Heater: 

• Turn off the water heater by pressing the power button.
• Unplug the power cord of the tankless unit. 
• Leave the water heater for 30 seconds. 
• Restore the power to your water heater and turn on the unit.

When to Seek Professional Assistance

If you fail to reset the error code 61 following the above steps, I recommend you call the Rheem Support Team or a certified technician for further assistance. 

Information credit:

• http://waterheatertimer.org/pdf/Tankless-error-code-61.pdf
• https://s3.amazonaws.com/WebPartners/ProductDocuments/47B18D5A-4E62-46BE-8FFB-3A34FD3087FF.pdf
• https://www.youtube.com/watch?v=JERj7D7dEtI