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

Rinnai error code 12

rreale Member Posts: 1
edited February 21 in Gas Heating

I have been getting error 12 intermittently for a few months. I took out the thermopile (manual calls it a thermocouple, but it has 2 wires that plug into the circuit board), and cleaned it. helped the first time , but not any more. When the unit is running(flame is on) my voltmeter shows approx 19 millivolts from thermopile. Is that enough. The unit is a Rinnai RCE-329a Natural gas ventless heater. The part I tested is RC-511-66-1. I believe this part was used in some of their older tankless water heaters. If you think i need a new thermopile, any idea of one that will fit. Rinnai no longer makes this part, and i cant find it. thx


  • HomerJSmith
    HomerJSmith Member Posts: 1,286
    It is probably a thermocouple and not a thermopile. The voltages between the two are vastly different. I would expect Rinnai to know what they are talking about. A thermocouple puts out about 30mv.

    You might have to jury rig a solution. Call Rinnai and ask them what they think. Talk to technical or engineering.
  • rreale
    rreale Member Posts: 1
    well, it doesnt have the copper sleeve that thermocouples generally have. it has 2 wires. I will try rinnai again, but the last time i tried they pushed me to a dealer, that says the part isnt made anymore or just doesnt call me back. johnstone supply and fw webb doesnt have anything close.
  • rreale
    rreale Member Posts: 1
    I called rinnai, they said it should it should throw 18 millivots. When i tested it threw 18-19, so it appears good. He said i needed to adjust the gas pressure. the manual states how to do this, but i dont have the proper tool to do this. Trying to find someone to work on it , is not easy
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!