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Rinnai Burner Shut Off When the Cover is On

Capt_K Member Posts: 1
edited February 2019 in Domestic Hot Water
Rinnai RU98i REU-KB3237FFUD-US, installed Aug 2014

Here is strange situation my plumber is trying to solve. When the cover is installed on the unit, with hot water demand, the burners run for a short period of time, then cut off, then sometimes come back on, then off. Sometimes code 12 is displayed. A code 10 was displaced once. If then cover is not installed, the unit runs just fine with both low and high demand hot water. Vent piping checked OK. This situation occurs even if the vent pipe is removed. Gas pressures checked OK. Regulator vent plug OK but was replaced. Even with the vent plug not installed the same thing occurs. The flame rods and igniter were cleaned.

It might be coincidence or not, but if the unit is running and then you go to install the cover, sometimes jiggling the cover or installing the screws seem to trip the burner. Rinnai rep does not believe this is an electrical short issue but I have might doubts.

Anyone have any thoughts?


  • Jellis
    Jellis Member Posts: 228
    i had a unit doing something similar to this and found the combustion fan faulty, When i had the cover off the unit it would fire up and run, but with the cover on it would not. basically any resistance put on the combustion motor would cause it to stop turning. Your plumber should be able to call rinnai tech support if he needs assistance testing the components.
  • nibs
    nibs Member Posts: 500
    On my e50, the clearance between the cover and the controls is quite small, if you are lucky you might find that the cover is pressing on the front cover of the box containing the buttons.