Rinnai E430 Error Code [Quick Fix]

Beginner Info, Tankless Water Heater

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The Rinnai E430 error code is definitely an important error code that needs quick response else it may lead to a weird situation for the user.

We’ve been receiving calls on a frequent basis from our clientele regarding the Rinnai E430 error code so we decided to pen down a post on it in order to help our clients as well as the readers of izzysmarthomeguide.com.

I’m sure that post reading this article on Rinnai E430 error code, you would be able to make an informed decision.

Nonetheless, in case of any doubt or query, feel free to reach out to us and our core team will be more than happy to assist you.

Does it make sense?

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


Few days back, one of our loyal customer complained that she is getting Rinnai E430 Error Code on her 8 month old Rinnai water heater and the error code appears when there is a demand for DWH or CH.

Once she resets the unit, it starts working well for few hours and then again the error starts appearing again as soon as the demand for hot water starts increasing.

Are you struggling with similar problem?

In such scenario, most of the time, the display water pressure would be reading 0 PSI and it may fluctuate when the demand for hot water surges.

In some cases, it will settle as soon as the unit reaches the desired temperature.

Even though there isn’t any leakage, probability is quite high that the external pressure gauge would be reading 22-23 PSI.

So, you might be wondering what’s the solution for this error, right?

First and foremost, you need to expedite certain steps on your own in order to check whether other things are clean and working properly or NOT.

For example, you need to check whether or not the circulator motor is spinning properly.

Secondly, make sure that the DHW input filter screen is clean, CH filter is clean, etc.

Try changing the speed of circulator pump from mid to high and note down the outcome.

By doing so, see whether the issue is resolved or getting elevated.

Then, try changing the speed to low and note down the outcome.

Moreover, you need to flush your boiler in order to get rid of hard water build up inside the unit.

Also, check the water quality with a TDS meter and make sure it is under the Rinnai’s specification range in order to avoid any last minute misadventure.

A possible solution for the Rinnai E430 Error Code could be hooking up an external gauge to the system.

In such situation, probability of one of the two sensors might not be working properly or expansion tank charge is wrong, or in the worst case scenario, bladder is useless.

You can fill pressure and set it same as bladder pressure on a cold to warm boiler.

Don’t forget to check the expansion tank for waterlogging along with bladder pre-charge pressure keeping the tank isolated.

[Important Points Related to Rinnai E430 Error Code]

  • When your boiler will have below 7 PSI, it will display Rinnai E430 Error Code
  • E430 diagnostic code will be present on the controller display and will not operate
  • Increasing the heating system water pressure is necessary for the operation
  • Between 7 – 13 PSI (0.5-0.9bar), operation will be limited (E430 diagnostic code will be present on the controller display)
  • An E430 diagnostic code will be present until the boiler senses at least 13 PSI (90 kPa)

It is recommended to fill the boiler with power supplied to the boiler.

If power isn’t supplied then it can lead to problems such as freezing and pump lockup.


  • Ensure all boiler components are installed correctly
  • Open the air vent inside the boiler
  • Power on the boiler
  • Open the fill valve on the filling circuit
  • Check the pressure on the controller and/or
    pressure gauge
  • Fill the boiler to a minimum of
    20 PSI (138 kPa) water pressure and a maximum
    of 30 PSI (207 kPa)
  • An E430 diagnostic code will be present until the
    boiler senses at least 13 PSI (90 kPa)
  • Check the heating system for leaks
  • Begin the deaeration process

Moving further, I’ll be explaining you the deaeration process in detail.

In order to expedite the deaeration process, you would be needing Philips head screwdriver.

Deaeration Steps

  • Remove the boiler’s front panel by removing the four screws that secure the panel
  • On the PC Board, press and hold the top, left black button
  • The Maintenance Required icon on the controller display will appear
  • Confirm whether all heat emitters and pumps are connected to the piping system
  • Fill the boiler to a minimum of 20 PSI (138 kPa) water pressure and a maximum of 30 PSI (207 kPa)
  • The deaeration process takes approximately 15 minutes for completion
  • After 15 minutes, the display will show “End”
  • The commissioning process is complete
  • On the PC Board, press the black button again to resume normal operation mode
  • Operate the domestic hot water or central heating to ensure the boiler operates properly
  • Close the air vent on the pump. After approximately one week, all air in the system should be eliminated via the air separator in the piping system

In case, you want more information about this error code then you can download the manual here.

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 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 in search for similar information.

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

Cutting long-story-short, the piece of information that we’ve shared in this post will help you in getting rid of Rinnai E430 error code, and in case, you’ve any doubt or query then feel free to reach out to us via the contact form and our core team will be more than happy to assist you.

That’s all, as of now:):)