Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Rinnai53 Stopped Working

I have a Rinnai 53 (date code 10/2005). Up until yesterday it worked okay. I say okay because showers routinely turned cold about 1/2 way in requiring me to turn water off and re-regulate. I flushed the system about 8 months ago hoping this problem would be fixed, but it continued. It was only a slight irritation and other than that the system worked fine.

Last night, midway through my shower, the water got cold and I never regained hot water again. This morning I checked the hard-wired controller and the panel was not lite. I pressed the on/off button, but nothing worked. I went outside. I could not detect any visual problems with the unit. I did turn the exterior switch (housed in a weatherproof electric box) off and back on, but the water is still not hot.

Does anyone know what the issue might be? Is it just age? I think the aforementioned flush 8 months ago was the first and only for the unit.

Any help would be greatly appreciated!


  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    Are you getting electrical power to it at all? Fuses? Circuit breaker?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England