Rinnai tankless water heater troubleshooting

Rinnai tankless water heater troubleshooting. Tankless heaters are one of the best inventions of today’s world. And if we talk about good tankless water heaters, the most reputed brand Rinnai is one of the best-known brands for its reliability.

If you have invested in Rinnai tankless water heaters, you don’t have to worry about a more extended period because their life span is almost 20 years.

Like all other appliances in the world of technology, Rennai tankless heater needs proper maintenance to work efficiently.

There is no doubt about the performance of tankless heaters by the brand Rennai, but They can still show Different types of errors.

But To diagnose those errors, a Self Diagnostic tool is installed in the Rinnai tankless heaters. The tool will monitor everything related to the tankless heater to maintain its functionality.

And we have specially researched those errors to build a proper guide for you that can help you in Rinnai tankless water heater troubleshooting.

Rinnai tankless water heater troubleshooting

Error codes of Rinnai tankless water heater

error codes of rinnai tankless water heater

If something goes wrong with the Rinnai Tankless heater, the self Diagnostic tool will show up different types of errors with numbers so that you can identify the problem and solve it.

But if you don’t know the meaning Behind Those error codes. Then you don’t have to worry because we are here to help you in detail.

We have specially organized a detailed troubleshooting guide so that you can identify the message Behind those codes and get rid of the issues.

Error Code 2: Frozen Burning Functions on the time of Freeze Protection Mode

If your tankless water heater is showing error code number 2, then it tries to indicate that heater will not work correctly when the desert protection mode is in the on position.

This is a pretty complicated problem that can happen with your tankless water heater. So we recommend you do not go above your head on such complicated problems and call a professional technician for problems to get them solved.

Error Code 3: Interrupted power Source at the time of Bath Fill

This Problem mainly occurs during bath fail. Error code number she tries to indicate that if a sudden power outage occurs, then the water supply will not continue flowing after the interrupted power source.

To solve this problem, you have to Switch between two options, ON and OFF. We recommend you locate a hot water tap and press both options more than once. This Mini step will solve error code number 3.

Error Code 05: Bypass Servo Valve Faults

bypass servo valve faults

This Problem could lie because of a faulty bypass Servo valve.

If something goes wrong with the bypass valve or gets broken, it is more than possible that your Rinnai tankless water heater will show up with code 05.

To eliminate the bypass valve problem, you have to Switch between the on and off options.

  • Step-1: the first step that you have to take is to shut the power OFF.
  • Step-2: Turn the power OFF, and turn it back in its ON position.

We hope that switching between the on and off options will possibly fix the error code 05.

Error Code 7: Dropped circulation Flow

dropped circulation flow

The first step you must take is to check if the Circulation flow is dropped. This Error will show up when the flow rate drops from 2m1 GPM.

  • Step-1: So ensure that the power supply is entirely efficiently produced in the Unit.
  • Step-2: Thoroughly check that water supply is efficiently Coming in the utmost Psi rate Of 30.
  • Step-3: After injuring the rate of ps, you now have to keep your eye on different connections of the pump wiring. Check if the connection is broken or damaged.
  • Step-4: After doing the above steps now, drain the whole tank and check if anything is blocking the water filter. Thoroughly uses a heat exchanger to flush it adequately in the case of blockage in the water filter.

Error Code 10: Obstacles In Air Supply

If your Rinnai tankless water heater is showing error code number 10, then it means that the Problem refers to the venting problems.

The Problem could lie because of the usage of wrong low-quality venting materials. Make sure that no idols are making their way into the functionality of the proper venting system.

Ensure that the measurement of the venting system is correctly applied by checking whether the diameter and length are within their limit.

If you clear all the venting problems after identifying every single Problem, then we are sure this problem will get solved.

Error Code 11: Defectiveness in the ignition heater

defectiveness in the ignition heater

An exam goes wrong if tankless water heaters are installed along with the ignition. Then the water heater will not work accidentally.

This Problem could cause because by the loose connections between the igniter and water heater.

So if you want to identify the problem, you have to check the wiring connection of an ig to see if it is working efficiently.

If they are not working correctly, retraining the connection may fix the error code 11.

Another possible reason for code 11 could be a blockage in the water heater, faulty solenoid valve, and defective installation.

Installing everything properly and removing the blockage will possibly fix the ignition error.

Error Code 12: Vanishment Of Flame

vanishment of flame

This Problem is severe because this could lead to the failure of the Rinnai Tankless water heater. As you know, if we talk about the heater, then flame comes automatically into our minds.

Because the heater is associated with the flame, and if your heater starts losing frame, the problem could lie in the power supply and Flame rods.

To fix the problem, you must examine the Builder of Dirt and grease on the flame rod and thoroughly clean it.

Loss of flame could be because of the disconnection of wiring and hurdles in the venting system.

Connecting the wires back and their place and removing the hurdles from the venting system will possibly fix code number 12.

Error Code 16: An excessive amount of temperature will lead to the reaction of thermal fuse

If your tankless water heater shows, error code 16-8 indicates the thermal fuse is reacting.

This can be because of blockage in the venting system, excessive blockage, build-up in the combustion chamber, or clogs in the heat exchanger and heating chamber.

To get rid of this error code 16, you must eliminate any hurdles that are not letting the venting system work correctly.

Another step you can take is to remove any blockage you can witness in the combustion chamber and the heat exchanger.

Error Code 19: Short Circuit

short circuit

This error code directly indicates the problems related to electric power. So we recommend you examine the grounding electric connections and all the short circuit parts.

Error Code 25: Blocked condensate trap

This Error can show up because of clogs in the drain pipeline. And fixing the blockage out of the condensate drain line will possibly clean it and fix the Problem.

If it doesn’t work correctly, replacing the condensate tank will be the only solution left Behind.

Error Code 31: Faulty Sensor

faulty sensor

Sensors play a crucial role in the tankless water heater; a problem could occur if their resistance value drops to the ideal value.

Replacing them is the only solution in such a situation where the sensor gets faulty.

Error Code 32: Water Line sensor wiring harness

If the sensor gets faulty on the Water Line, the reason could lie in the loose wiring or a defective sensor.

Do a one-step simple examination process you have done above in error code 31.

Error Code 33: Defective heat exchanger system

If something goes up or down with the sensor, examining its wiring connection and fixing the blockage will possibly fix the job.

It doesn’t work with sensors, so replacing them is the only solution.

Error Code 34: Damaged air sensor

The problem with census occurs because of the unbalanced resistance values in the sensors.

And if a sensor gets damaged, Water will start showing up code 34, which means that if the sensor gets adequately damaged, then replacing it will be the solution.

Otherwise, fixing the wiring and setting up any hurdles in the vending system will be the fixture technique.

Error Code 41: Faulty freezer Protection Sensor

If the freezer protection Centre gets quality, its wiring is likelier to break or loosen. You have to repeat the steps listed above for the forty sensors.

Removing the hurdles>Checking the resistance value> Replace the Faulty Sensor.

Error Code 52: Defective Solenoid Valve

defective solenoid valve

If solenoid the valve gets defective, 10 reasons could lie in the resisting value, which is dropping. Another reason could lie Into The Lost connection between wiring and.

Fixing the connection between wiring and setting the resisting value will possibly fix the problems related to the solenoid valve.

Error Code 57: bi-Metal switch is not functioning

Examine the bi-metals switch and check if you can do something to set it in a good position. If It doesn’t work correctly, then replacing the sensor will fix the Error.

Error Code 61: Defective fan motor

If the fan motor gets damaged or its wearing stop sticking in its place, then you have to examine the resistance value to check if it is with an inaccurate value limit.

Error Code 65: Defective Controlling valve Of Water flow

defective controlling valve of water flow

If your tankless washer is showing up with this Error, then the backbone of this Error is the bath fill function.

If something goes up or down with the bath fill function, then calling a plumber will be the only fixture because This function is pretty complicated.

Error Code 70: Inoperative PC board

If the PC board gets faulty due to any possible reason, then all you have to do is to check its connections thoroughly.

If something you feel to change, immediately changing it on its point will possibly fix the Problem.

But If the PC board goes faulty over the board, then replacing it would be the only solution.

Error Code 71: Flawed Solenoid Valve

The solenoid valve is something that needs prior attention. And if it gets flawed, you need to rearrange the whole electronic board.

Error Code 72: Non-Functioning Flame Sensor

non functioning flame sensor

This Error could show up because of dirt build-up on the flame rods. But if we include other reasons for the non-functioning flame sensor, then a lost connection between its wiring can also make its way to the flame rods.

When we witnessed this Problem on our Rinnai Tankless water heater, we used Sandpaper to clear out any dirt and debris on the flame rods.

If build-up and/or lost connections are not a Problem behind the non-functioning flame sensor.

The Problem is more complicated than we thought. In such a situation, replacing the Flame sensor will be a Fixed solution to eliminate the Error.

Error Code 73: Malfunctioning Burner Sensor

If a connection between wiring gets lost for any possible reason, it can stop the functionality of the burner sensor.

To retrain the sensitivity of the burner sensor, fixing its wiring and Replacing it will be The fixture.

Error Code 79: Malfunctioning burner Error

If your tankless water heater is trying to Show Error no. 79, then Problem follows the type details we have listed above for the previous Error.

Rinnai tankless water heater is heating water

rinnai tankless water heater is heating water

Suppose your Rinnai tankless water heater unit is working correctly and still not providing hot water. The Problem could lie in the different things.

  • Small Size Of Water heater

If your tankless water heater is small, it is more than possible that it cannot provide a large amount of pressurized water heater.

  • Overloaded Rinnai tankless water heater

Sometimes we tend to use many different appliances that ask for hot water to run its functionality. in such a situation, a water heater gets overloaded and stops providing hot water.

All you have to do is remove the thermal fuse of a different mechanism so that your tankless water heater can lose weight and start working up properly.

  • Faulty Heat exchanger Plug

If the heat exchanger plug goes ups or down, then you have to do is to examine the heat exchanger fins. If something gets faulty, exchanging them or examining secondary heat exchanger fins may fix the Error.

  • Conflicting gas supply

If the gas line gets interrupted, the water heater will not produce hot water, and the temperature controller will show faults.

In such a situation gas burner will end up working, and hot water faucets will stop showing up with hot water.

All you have to do is to fix the temperature setting and temperature controller so that your hot water faucets will start releasing hot water.

  • Blockage in the components of the gas heater

This Problem mostly happens in the areas where the humidity level is touching its limits or calcium in the water is too strong.

Humidity levels and calcium start building up layers on the components, which leads to the blockage of different components of the Rinnai tankless water heater.

Removing that build-up with removing solutions will let the water heater start heating again.

Rinnai tankless water heater starts beeping consistently

rinnai tankless water heater starts beeping consistently

Well, beeping doesn’t occur most often in the Rinnai tankless water heater, but if it starts beeping, it tries to indicate different problems.

  • Overloading tank heaters

The very first problem is overloading. If your tankless water heater is constantly beeping, the water heater is overloaded with water.

In such cases, immediately remove the water supply and drain excessive water.

  • Leakage of Water heater

If water starts leaking, the problem could get even worse because water leakage can affect the water circulation sy and stem, which can stop the functionality of different things.

  • Leakage in the Gas Line

We all know that beeping always indicates something serious issue. If something goes wrong with the gas line then it will start leaking. The leaking of gas lines is something that we can’t ignore.

If your tankless water heater is constantly beeping, you must immediately look for the gas line. As if it is leaking or not!

In case of leakage, you have to immediately contact your gas line provider or a professional plumber so that they can help you to fix the leakage.

  • Defective components

Suppose components of your tankless water heater get faulty. Then all you have to do is identify the problem and check if you can fix it with the guide we have listed above or not.

Stock anytime, then you must need to replace the defective component so that your tankless water heater stops beeping.

  • Shortage of fuel

We know that we also need fuel if we are talking about a gas heater. If you go down to its limit, your tankless water heater will immediately start beeping to tell you that the fuel is getting low to its limit.

So filling the fuel will possibly fix the beeping Problem of your tankless water heater.

Steps To flush The Rinnai Water Heaters

steps to flush the rinnai water heaters

If you see your water heater start showing up different errors like a blockage in the pipelines or blockage in the valves. Then you have to flush the Rinnai water Rinnai occasionally.

well, if you don’t know the process of flushing your Rinnai water heater, then you don’t have to worry much because we are here to help you with a detailed step-by-step process of flushing out the Rinnai water heater.

Step 1: gather Important Material

to start your process smoothly, you have together some necessary materials or tools that we have listed down.

  • Adjustable screwdriver
  • A Bucket
  • Sump Pump
  • Tester
  • Adjustable Wrench
  • White distilled Vinegar

Step 2: Switching OFF the Functions

After getting all the essential material, the first step that you have to do is to shut down different types of power components.

Power Down The primary power source and All the related temperature valves.

Step 2: Dissembling Purge Valves

The next step that you have to take is to locate The Purge valve and try to dissemble it By eliminating the Purge valve caps.

Step 3: Termination

terminating The Purge valve caps are now used, and an adjustable wrench the connection of water valves and hose lines.

Step 4: Add white vinegar

You must use a bucket and connect the second pump in this step. But before doing that, white vinegar and add it to the bucket.

Step 5: Removal Process

Vinegar will help eliminate and cut off the water hoses and pipes. Let it rest for about 10 to 15 minutes in this step, and then turn the tap water in an ON position for almost 10 minutes.

Step 6: Buildup Removal

This step sprints everything adequately so any type of embedded build-up can be eliminated.

Step 7: Reversing the steps

Reverse the process by putting The Purge valve caps on their water and gas supply back in their suitable position.


Chennai Is a well-known brand for the poorest, highly efficient technology it provides in tankless water heaters.

When we buy a new appliance, we confuse its installation and usage. This confusion leads us to different problems. If this is also happening to you, you must look for some Rinnai tankless water heater troubleshooting steps.

When you are lucky now that you are here as we have listed a detailed guide that why Rinnai’s default indicator of a tankless water heater is behaving in a certain way.

The most common reasons that lead to the failure of tankless water heater are fault gas control valve, damaged or lose connections, malfunction in hot water faucets, flame sensing device fault, disbalances temperature setting, faulty gas solenoid valves, disturbance in the water circulation system, flame failure solenoid valve circuit fault and different problems with hot water taps.

We have listed everything you need to know about your Rinnai tankless water heater.

If something goes wrong with the water heater there, it can stop the functionality of many other home appliances you were using with the help of a tankless water heater.

What are you waiting for if your tankless water heater behaves a certain way?

Grab your tools and start fixing your Rinnai Water heater so that you can enjoy endless water heater.

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