Rinnai i120c combi boiler losing pressure (error code 430)

[Fitter30]

Page 2

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/UPS15-58FC-install.pdf

 

[GReynolds929]

I think it was the circulator, as I adjusted it and now since I done this no error code.

Shaft of the motor needs to be horizontal, not vertical or diagonal.

 

[Sponsor]

 

[John Gayewski]

I'm gonna guess the circulator didn't cause the problem, but we'll see.

 

[SalMazz]

Your circulator is upside down. I don't think it's causing your problem but it's a pretty fundamental mistake.

I'm not that familiar with rinnia, but have you cleaned the unit since installed? How's your water quality.

Thank you i fixed the circulator and this was the problem. No error code since!!

 

[SalMazz]

Help system was working from February 29,2025 until March 12, 2025 with no error code E430 once I adjusted the circulator. Now I am getting the E430 on occasions sporadic. Any thoughts maybe pressure switch?

 

[Fitter30]

Help system was working from February 29,2025 until March 12, 2025 with no error code E430 once I adjusted the circulator. Now I am getting the E430 on occasions sporadic. Any thoughts maybe pressure switch?

What's the water pressure? Minimum is 13 lbs.

 

[SalMazz]

What's the water pressure? Minimum is 13 lbs.

I have been in touch with Rinnai, and it seems that the E430 error on the combo boiler is due to sediment buildup causing the issue I was experiencing. I cleaned the filter screen under the boiler, which was dirty, and I plan to flush the system with vinegar. Additionally, I will flush my heating lines with a cleaner, isolated from the heating unit, when the weather permits. My pressure was fluctuating by the way and I did not see this at first but when I checked probably due to what I mentioned above. Hope this helps someone who has a similar issue.

 

[John Gayewski]

Post 17 of this thread.

 

[Fitter30]

I think it was the circulator, as I adjusted it and now since I done this no error code.

What brand is the air device ( micro bubbler)?

 

[SalMazz]

help still getting e430 code with Rinnani Combo boiler. It happens even when not asking for any hot water just when it cycles. I can't figure this out. Had posted pictures before maybe if I can I post a video.

 

[SalMazz]

Shaft of the motor needs to be horizontal, not vertical or diagonal.

That was not the issue on the Rinnai boiler there is a factory setting that needed to be changed. The factory setting is for having a setup where you have continuous hot water as soon as you open the faucet. This is in the fine print and caused E430 error code.