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Help Rinnai tankless heater RL75 No Ignition

TimRTimR Posts: 2Member
edited March 2017 in THE MAIN WALL
Hi There, We have a three year old Rinnai RL75 tankless water heater that flows water through it, but will not ingnite. It shows no error codes, the propane tank is 80% full, vent is clear. I have powered it off and on. I also tried entering into Rinnai error code mode, and the unit will just scroll --01--02--03--04--05--06--07--08--09 repeat. I guess that means it is showing no errors? Any ideas would be great.


  • Aaron_in_MaineAaron_in_Maine Posts: 315Member
    Check the screen on the inlet cold water line. If it is not sensing enough flow it will not fire.
    Aaron Hamilton Heating
    [email protected]
  • psb75psb75 Posts: 155Member
    and"deeper" than the cold water screen, the flow switch could be crudded-up, or its electronics messed up.
  • TimRTimR Posts: 2Member
    Thanks for the replys.The water screen I checked and we have good flow. I'll look at the flow switch. Thanks Again!
  • JackJack Posts: 1,044Member
    I suspect that as noted, the small turbine wheel inside the CW inlet valve is jammed. I think it is easiest to remove the valve. Drop the 4 screws on the bottom of the cold water inlet and disconnect the internal pipes. They are O-ring joints so be careful with the O rings. There is a small snap ring internal that holds the turbine in place. Pull the turbine apart...carefully, and the turbine wheel and shaft will fall out. Wash thoroughly, re-assemble and blow through the turbine. It should spin freely. Reassemble and report back.
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