Rinnai Error Code 57

Beginner Info

Rinnai Error Code 57
As an Amazon Associate, I may earn from qualifying purchases at no extra cost to you. All the products recommendation links on izzysmarthomeguide.com will navigate to Amazon

In this post, I’ll discuss various aspects of the Rinnai Error Code 57 and how to fix it.

Irrespective of whether you’re a first-time buyer or a seasoned professional, you can efficiently expedite the Rinnai Error Code 57 fixing on your own in a hassle-free manner.

Nonetheless, in case of any doubt or query, feel free to contact us via izzysmarthomeguide.com, and I would be more than happy to assist you in the best possible way that I could.

So, without any further ado, let’s begin…

Rinnai Error Code 57 should be dealt with on time in order to prevent any last-minute misadventure.

Ignoring this error may lead to a bigger problem.

The Rinnai Error Code 57 is caused due to Burner Overheat Bi-Metal Switch and needs to be taken care of well in time.

Most of you would be aware of the fact that there are two bi-metals located on the rear of the burner assembly.

And, if any of the two opens, your unit will start displaying the Rinnai Error Code 57.

Your tankless unit may or may not operate when this code will start displaying.


This error code will STOP displaying only after you’ve fixed it.

Once you’ve fixed the error, the next thing that you need to do is to reset the unit.

All you need to do is to first turn the power off and then turn it on.

In simple words, Rinnai Code Error 57 will appear on your unit if the PCB will not see continuity through the two overheating switches.

The overheating switches are part of the thermal fuse/overheat harness but are wired in parallel to the thermal fuse as well as overheat switch 1.

Moreover, if the overheated switch 2 circuit is open code 57 will be posted immediately once power is applied to the unit.

However, the operation of the unit is not necessary for the troubleshooting purpose which is definitely a piece of good news and will make your work easier, isn’t it?

Make sure to disconnect the water heater from the electrical power before expediting the troubleshooting process.

Note: Turning the unit off at the control panel will not be sufficient.

Rinnai Error Code 57 Troubleshooting

By expediting the below-mentioned steps, you would be able to troubleshoot the Rinnai Error Code 57 without any difficulty in an epigrammatic span of time.

  • Ensure the connector with the white and red wires (connector B7) is securely connected
  • If the connector is secure and the code 57 is still posted when power is applied, disconnect power then place a jumper wire* from the white to red wires of connector B7
  • If the code 57 is not posted when power is restored replace the thermal fuse harness
  • If the code 57 reappears, disconnect power and gain access to the PCB
  • Do not disconnect any wiring from the PCB
  • Place a jumper wire* from connector G, pin 8 to connector E, pin 10
  • If the code 57 does not post and the unit operates, replace the sensor wiring harness
  • If the code 57 reappears replace the PCB

*Note: Make sure that you use jumper wire only for testing purpose. At the same time, you also need to ensure that you don’t leave jumper wire connected after testing is completed

It’s A Wrap

First and foremost, I would like to thank you for being with us till the end.

Secondly, I would like to bring to your notice that I along with my core team have put loads and loads of effort in coming up with this idiosyncratic superlative piece of information.

And, in case, you liked our effort and wants to appreciate us then please do share this post with like-minded people and the ones who are looking for similar piece of information.

After all, sharing is caring, isn’t it?

Cutting long-story-short, the Rinnai Error Code 57 troubleshooting steps shared in this post are easily to expedite and will not consume much of your time.

Most importantly, you can expedite them on your own without a need for a certified technician.

However, if you’re not sure about the aforementioned steps, please do contact a certified technician for getting proper advise.

We’ve been recommending the aforementioned troubleshooting steps to our clientele and the feedback that we’ve received so far are positive and promising.

That’s all, as of now:):)