Rheem tankless water heater code 29 is the error, indicating that the heat exchanger outlet temperature is too low. This’ll only apply to the Mid-efficiency models. Besides, when there is an abnormality with the neutralizer water level electrode on your Rheem high-efficiency models, you’ll see error Code 29 on the display.
The major reasons for occurring this error code include:
- Blocked heat exchanger fins or air intel screen
- Clogged neutralizer
- Blockage in the condensate drain line or isn’t correctly routed (Condensing Only)
Anyway, to overcome the problem, remove the blockages from the heat exchanger and air inlet screen. For a condensing unit, examine both the neutralizer and drain pipe for any blockage and remove it. Plus ensure, the neutralizer water level electrode is properly connected to the heater.
Seems confusing? Not more! Let me provide you with practical and straightforward solutions to erase the error code 29 from your Rheem tankless water heater!
Table of Contents
Possible Reasons & Solutions For Rheem Tankless Water Heater Code 29 [Quick Overview]
Before heading over to the details, let’s make your further reading easier through this quick table highlighting all the reasons and recommended fixes for the Rheem tankless error code 29.
| Probable Reasons | Recommended Fix | |
| Rheem Mid-efficiency Tankless Water heater | Blocked heat exchanger fins | Remove the dirt and debris from the heat exchanger. |
| Abnormal resistance reading in the heat exchanger thermistor | Test or replace the bad thermistor | |
| Blocked air inlet screen | Clean out the air inlet screen | |
| Rheem High-efficiency Condensing Tankless Water Heater | Clogged neutralizer | Clean out the neutralizer |
| Blocked condensate drainage system | #Remove the shipping cap from the service drain line. #Clean the blockage in the condensate drain line. #The drain should not have any unnecessary “P” trap and be installed correctly. #Check for a pinch in the condensate drain line. #Make sure the drain pipe is in the correct diameter. |
How Do I Fix Rheem Tankless Water Heater Error Code 29?
In general, the error code 29 defines the different meanings in the case of mid-efficiency and high-efficiency Rheem tankless water heaters. But for your convenience, I am going to disclose all the responsive factors for this error code on both models based on my personal experience.
Let’s dive right in…..
Rheem Mid-efficiency Tankless Water Heater Error Code 29: Outlet Temperature Is Too Low
If you’ve a Rheem Mid-efficiency tankless water heater and display the error code 29 on the remote display, it means that the heat exchanger temperature is too low. Here are all the probable reasons for this error with the effective fixes:
1. Blocked Heat Exchanger Fins
When operating the tankless water heater, it’s an important point to check out the proper operation of the heat exchanger. In this instance, the heat exchanger should be neat & clean in order for your unit to operate efficiently and safely as possible.
In case there is a small amount of scale or dirt build-up on the exchanger, it makes it harder to work than necessary.
When the unit puts extra pressure on this equipment, it fails to exchange the heat and causes your heater to trigger the error message 29.
How To Fix:
Now you may wonder how you will determine that the heat exchanger isn’t in normal operation. I’ve got a quick trick for you which I always apply in my water heater:
- First up, activate the Maintenance mode on your Rheem remote display following the guide.
- Next, push the up arrow button to select a diagnostic table. It’ll be designated by a letter and displayed as the second digit.
- Well, press the down arrow key until you get the 1Y table.
- Use the down arrow key again and change the number in front of Y to 4.
- While displaying the ‘4y’, you will get the temperature reading of the heat exchanger. Now verify the heat exchanger temperature and compare whether it matches the indicated by 4y. If yes, the heat exchanger is dirty, that needs to be cleaned.
To clean the heat exchanger:
Step #1: Turn the power off the power supply to your water heater first by turning off the breaker at the junction box. Turn off the gas and water supply as well.
Step #2: Now, remove the front cover and access the heat exchanger, disassemble it from the connection for cleaning. Set it on a flat surface and remove any dirt or debris with a wire brush.
Step #3: In case you get black soot or scale from each chamber, use a brush to loosen it. A damp cloth with cleaner can also be used here to remove any soot or scale.
Step #4: Take a strong shot vacuum to vacuum the entire block assembly. After cleaning, reassemble the heat exchanger, attach the front cover, and restore the power supply. Now check for any error code.
2. Abnormal Resistance To The Heat Exchanger Thermistor
In case of improper temperature reading in the heat exchanger even after cleaning, abnormal resistance to the exchanger thermistor can be the big culprit.
The thermistor is an essential part of the water heater that is designed to monitor the temperature while delivering hot water to your faucets. It also alerts you on scale build-up in the heat exchanger to prevent it from overheating.
Anyway, due to abnormal resistance, it will fail to regulate temperature and throw the error code 29 on the Rheem remote display. So, in this step, you need to check out the resistance readings of the thermistor to determine the malfunction of this element.
Here is all you need to follow:
How To Fix:
First off make sure you have turned off the power supply to your water heater. Press the power button on the remote control and unplug it from the power connection.
Now unscrew the front cover panel and set it aside. Next, access the control board and locate the connector D on the board.
- Measure resistance between Black #3 & YELLOW* #5 wires and it should give reading in between 7K – 23K Ohms.
- Next, remove Molex connector R and locate the black #3 wire of the connection. Measure the resistance of this back wire and the black wire at Yellow* Molex located behind the Control Board for the 7K – 23K Ohms.
- Also, check continuity from Yellow* #5 wire at Molex connector “R” and Yellow* wire at Yellow* Molex and you should get the same reading.
In case there is any malfunction in the reading, consider replacing the connector R or the complete heat exchanger thermistor with the new one.
3. Blocked Air Inlet Screen
If you’re experiencing error code 29 on your Rheem Performance Platinum tankless water heater, a blocked air filter is one of the major reasons to check. The air filter in a tankless water heater is mainly designed to protect the sensitive part of the unit from all dust, debris, hair, and any other pollutants.
As for always filtering the contaminants from the air, plugging the element with dirt and debris is quite obvious. Thus regular cleaning and maintaining of the filter is quite essential to allow the heater to breathe better and extend its life expectancy.
Anyway, when you have a blocked air filter, the fresh air flow fails to enter the system interrupting the heat exchanger operation and causing error 29 on the display.
How To Fix:
Inspect the air filter for any blockage. In this instance, you need to unscrew it from the connection and take it out. Place the dirty side up and vacuum out the stuck debris.
If needed, clean it in a utility sink by running water over it and cleaning any dirt, dust, or debris caught in the filter. Finally, let it dry or wipe it with a fresh cloth. When done, reconnect the air filter back in place.
Rheem High-Efficiency Tankless Water Heater Error Code 29: Water Level In The Neutralizer Isn’t Draining Correctly
The Rheem tankless error code 29 in the condensing model indicates an issue with the condensate drainage of the system. Basically, a high-efficiency condensing tankless water heater uses a drain line that is equipped with a neutralizer to drain the condensate.
When the water is heating, it produces acidic condensate that processes with the neutralizer and passes through the drain line.
In case the drain line is blocked or incorrectly routed, the condensate fails to pass to the end drain and triggers the error code 29 on the remote display.
There can be a variety of reasons for this error code relating to the neutralizer and drainage system.
Don’t worry, we will discuss them in detail in the next sections with effective solutions:
4. Clogged Neutralizer
If there condensate is not able to pass and hence backs up into the water heater, the best chance is the neutralizer is clogged for why the water level in it fails to drain correctly.
The neutralizer drainage ports inside of the unit might be blocked or there is a plug on the condensate drain port at the bottom of the unit.
How To Fix:
As a solution, you will need to inspect the neutralizer for any blockages. If it is filled up, simply check for the shipping cap at the bottom and remove it.
Now try to clean out the blockages in the neutralizer by draining some water from the neutralizer using the service drain line. In this instance, first off, make sure that the service drain is clear and not clogged. It should be a single line with no trap and loops going to another drain.
If so, the water will pass through freely, cleaning all the blockages from the neutralizer. In case the neutralizer is beyond cleaning, you need to replace it with a new one.
You can do it by yourself if you have a Rheem neutralizer replacement with you. Just follow the below effective video to get the details of the process.
If you’re technically inclined, we’ll recommend to hand over the task to a professional one.
5. Malfunctioning Condensate Drainage
Besides the blocked neutralizer, malfunctioning in the draining system of your water heater is another big culprit to blame for Rheem error code 29. It is important for your water heater to drain the condensate properly into the end drain as the remaining condensate in the neutralizer can potentially damage the water heater.
In case, the drain line is clogged or incorrectly installed, it will fail to pass the condensate freely. Thus in this step, you need to examine the drain line for any blockages and clean it if needed.
Despite clogging, there will be several factors for the malfunctioning draining system of your water heater. Have a glimpse to the below reasons with the recommended solutions:
Reason#1: Clogged Or Frozen Drain Line
First off, inspect the drain pipe for any solid objects. Poke with a stick in the drain line to dislodge the debris and clear the clog. At times, it would be just some minor blockage that requires cleaning.
For instance, use a plumber’s snake or brush and push it up or down the condensate trap to unclog the drain line.
You may need a vacuum cleaner as well to suck everything out that is stuck. In case the vacuum doesn’t work, you can use a drain gun for cleaning.
It will effectively push out slime, dirt, and debris from the drain pipe by firing high-pressure gas from the heater condensate drain.
In case it is colder months, the drain pipes get frozen with the contents inside. This is something that can, unfortunately, happen if the drain pipe of your water heater is lying outside of the house. Due to a frozen pipe, you won’t get the condensate out to the end drain pipe.
As a solution, use a hairdryer on the frozen section and thaw the pipe. As an alternative, you can use a heat lamp a few feet away from the pipe to warm it up. Besides these, a heating pad or hand warmers can be used to unfreeze the piping.
Tips: To make sure that this problem won’t occur with you next time, install the drain pipe in an area of your house where the temperature is regulated constantly. Also, try to cover the pipe with an insulating material during the freezing temperature of the colder months.
Reason#2: Drain line has unnecessary “P” trap
If there are any additional traps in the condensate drain, the unit will fail to drain the condensate properly, causing a backup and a 29 code. Thus in this step, check for unnecessary P traps in the drain line. If so, you need to remove it with the help of a professional.
Reason#3: The Diameter Of The Drain Pipe Is Not Wide Enough
If the diameter of the drain pipe is not wide enough, you will face issues in draining the condensate from your Rheem tankless water heater. It leads to bigger issues if there are even any clogs in this small pipe.
Anyway, the drain pipe of a tankless system should be more than one or two inches and always sloped towards the end drain point. Insect the pipe diameter of your unit through a professional and replace it with a wider pipe.
Reason#5: The Drain Line Isn’t Installed Correctly
Improper positioning of the drain pipe would be another big reason why the tankless water heater isn’t draining accurately and causing the Rheem code 29. If the pipe is placed horizontally, the condensate won’t be able to go to the endpoint and reach back into the water heater.
Thus, make sure that the pipes are vertical and sloped so that gravity can help the condensate to pass through the endpoint.
Reason#5: Use of Incorrect Pipe Material
The use of metal piping can be one of the big issues in the case of draining from your water heater as it tends to corrode and has a chance of deteriorating quickly.
Also, the metal pipe reacts with the acidic condensate and creates many solid materials, clogging the pipe. Hence it is recommended to use the plastic pipe fitting to prevent any kind of reaction with the acidic condensate.
Reason#6: The Drain Line Is Too Long
Last but not least, you need to check that the drain pipe to pass the condensate of your water heater is not too long which is out of your reach. It should be short enough as the manufacturer’s instructions and direct to the endpoint as much as possible. We will recommend to hire a skilled one for you to handle all the tasks for you.
FAQs:
How Often Should I Change Condensate Neutralizer In My Condensing Tankless Water Heater?
As a general rule, you should change the condensate neutralizer of your tankless water heater once or twice a year if necessary. The more acidic your water is, the more you’ll need to replace the element to maintain the heater’s efficiency.
Why Proper Condensate Neutralizer Is Necessary In A Tankless Water Heater?
Any gas-fired condensing tankless water heater must require a neutralizer to treat the acidic condensate from the heat exchanger. It’s essential as acidic condensate can cause serious damage to the pipes and the elements of the water heater.
What does Rheem tankless water heater error code 14 mean?
Rheem tankless water heater code 14 is the error indication of the failed overheat limiter. But in the high-efficiency condensing model, the code defines that the high-limit switch is tripped due to the rising temperature of the unit.
Why is there no power to my Rheem tankless water heater remote control?
The main reason for the Rheem tankless water heater no power to the remote includes a bad wiring connection between the unit and the remote. Besides, the defective PC board can be the reason or you may have a defective remote control that needs to be replaced.
In Closing!
Rheem tankless water heater code 29 is the most common error for those users who are not regular in proper maintenance of their Rheem heater. The error is a clear indication that you have problematic condensate drainage on your condensing unit.
In this case, clean the neutralizer and set the water level electrode correctly. Besides, make sure that the condensate drain line is correctly routed and has no obstruction.
If you’ve got a mid-efficiency model, remove all the dots and stuck grims from the heat exchanger and air intel screen.
In short, we can see that you need to ensure the proper maintenance of your water heater. Only then you can prevent this type of error code from your Rheem unit and make it more efficient while in operation.
To get more details on how to maintain the Rheem tankless water heater with the proper methods, take a look at our comprehensive guide, disclosing all that you need to know!!!