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Help !!! Cir pump wont stop running !!!

Brad White
Brad White Member Posts: 2,398
Could be any number of things but I would start with the valve end-switch. It may have a jumper across it or is stuck on stupid. The valve motor may be shot and replacing it would take care of that as a variable. Can you get a new one installed to see? It may be that simple and would cover a number of possible causes.

I would start there, checking for current across your circulator TT's at that relay and working back towards the valve.

Moving up the food chain, might your thermostat be faulty or the wires crossed? Again, check for any shorts or jumpers. (I have seen jumpers installed for testing and forgotten.)

May also be an aquastat issue especially if you are using the boiler to heat your domestic hot water. That would cause the boiler to run potentially to high limit and your zone valve may be incidental to that.

Just some perhaps obvious points; the real techs will have more I am sure.
"If you do not know the answer, say, "I do not know the answer", and you will be correct!"

-Ernie White, my Dad


  • Richard_21
    Richard_21 Member Posts: 1
    Cir pump wont stop running !! ??


    I have oil heat with taco zone valves. One zone is staying open causing boiler to run from time to time, heat is comming thru the open zone. Any ideas what could be causing this???

  • Robert O'Brien
    Robert O'Brien Member Posts: 3,537

    than playing guess your best and replacing parts that are not needed.Why not just call someone who can fix it the first time.Probably cheaper too if you guess wrong the first time.JMO

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  • Joe Mattiello
    Joe Mattiello Member Posts: 703

    the Taco 570 series zonevalves fail closed. you mentioned the valve is stuck open, and the endswitch obviously closed keeping the boiler running. Did you try disconnecting the thermostat to see if the valve closed? perhaps it's a faulty thermostat? If it's not the thermostat, it might be a good idea to change out the valve acuator. fuel oil is approx. 2.55
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
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