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WM ultra 155 circulator pump runs constantly

Rikster66 Member Posts: 1
I installed a WM Ultra 155 in 2008. It's been mostly trouble free. Yesterday I noticed that my main house heat circulator (circulator 3) was running with the boiler in standby mode. Are there any relays inside or behind the control module that may be stuck or is it time for a new control module?
I had a leak last year on the circulator flange that leaked down and ruined the display and blower motor. but everything has been running fine ever since.


  • kcopp
    kcopp Member Posts: 4,397
    Could be a bad thermostat. Could be a shorted wire. Could be a bad external relay...
    I dont think it has to do w/ the boiler.
  • Zman
    Zman Member Posts: 7,553
    If you remove the wires from 1 and 2 does the circ turn off?

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • mattmia2
    mattmia2 Member Posts: 9,475
    Form your question I assume it is zoned by circulators and not zone valves? What controls the circulators? Is there a zone control panel?