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Taco RMB controller cycling power

Hi - Can anyone suggest why a Taco RMB controller board would start power cycling ? When you turn it on it goes through its self-check cycle, reports no errors, then goes into control mode reporting the outdoor temperature (exactly as it should). A few seconds later the relay clicks and the unit goes through that cycle again.


  • STEVEusaPA
    STEVEusaPA Member Posts: 5,302
    edited February 2019
    Hard to say without being able to check it with a meter. Does sound like something wrong internally.
    There are a few Taco people who frequent here.
    Im sure one of them will pop on tomorrow.
    Did you try running the test routine?
  • Joe Mattiello
    Joe Mattiello Member Posts: 621
    Hi Jim
    Once it goes through the test mode, it should resume operating in what ever mode you have it set up in. Unless, one of the sensors is bad, and it can't perform normally. If you take the screw out of the center of the control, remove the control easily with out unplugging wiring strip, there is a manual/normal black toggle switch, place it in manual, and see if both pumps operate at full compliment. If they do, then it's one of the temperature sensors that's bad, or the control.
    Contact Taco Tech support 401-942-8000 for more information
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
    Rich_49Erin Holohan Haskell