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Older Rinnai r85 with replacement control board error 34

Help please!


  • Larry Weingarten
    Larry Weingarten Member Posts: 3,137
    edited February 2021
    Hi, I see that error 34 means "Combustion Air Temperature Sensor Faulty". So, if you're good with this sort of thing, I'd start by checking wiring connections and draft to make sure there are no bad connections or anything impeding air flow, in or out. Next would be to find out what the sensor should read and see how yours compares. It would be nice if Rinnai could supply you with a troubleshooting flow chart!

    Yours, Larry