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UT Controls 1013 circ pump runs continuously

maximac Member Posts: 5
I have a Trianco Heatmaker Mark II hot water heat and DHW boiler. I noticed the other day that the circulator pump was running though the thermostats are off (its summer ya know :-). The indicator lights all seem normal, the boiler is making plenty of hot water, its just the circ pump runs all the time. Any ideas? This can't be normal is it?


  • maximac
    maximac Member Posts: 5
    Also, its a UT Electronics Control series 1013 integrated boiler
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,594
    Are the radiators hot?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • maximac
    maximac Member Posts: 5
    no. The valves that allow water to the radiators are closed.
  • maximac
    maximac Member Posts: 5
    ...And Hello Ed. Nice to met ya!
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,594
    edited August 2022
    You will want to see if there is a problem with the thermostat or wires from the thermostat to the boiler. The internal wiring to that system has several proprietary controls like pressure differential control, thermal cut out and others that can be found here https://www.heatmaker.com/

    Since this company went out of business and was purchased by Laars (famous for pool heaters) the guys at https://www.heatmaker.com/ have found as many of the old parts (still new in the box) as they can to help homeowners and contractors keep those old things running.

    So first you need to see why the circulator keeps running. That is a function of the thermostat that operates a control that turns on the circulator.
    In this wiring diagram the Red wire and the White/red wire shown in the circle get connected to the UT control on the 9 pin connector. If you can find where the thermostat wire goes into the boiler junction box, you can disconnect that low voltage wire and see if the circulator stops. If it does, then the boiler is fine and your problem is in the thermostat or wires to the thermostat.

    I hope this helps
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • maximac
    maximac Member Posts: 5
    Thanks Ed. I'll give it a try. I found the manual online but there was no troubleshooting for this problem. Its probably getting time to retire the old boiler as its nearly 30 years old.
  • 109A_5
    109A_5 Member Posts: 1,344
    maximac said:

    I have a Trianco Heatmaker Mark II hot water heat and DHW boiler.

    "and DHW boiler"

    So you have the HW version ?

    The "HW" series provides domestic hot water as well as hydronic
    space heating. It includes an insulated storage tank through
    which boiler water is circulated.

    If so you may want to check the status of:

    (HW-M2 Series Only)
    The Priority Relay is a normally open single pole relay which
    accepts a 24 VAC signal from the low limit aquastat and the
    T-T wires to provide 120 VAC power to the system circulator
    when the tank temperature remains above 150∞F.

    If you have the H(P) version

    The "H" and "HP" series boilers are designed to provide hot
    water for space heating, and can be plumbed to an indirect
    water heater to supply domestic hot water.

    (H(P)-M2-Series boilers only)
    The Time Delay Relay controls the unit pump and keeps it
    operating for approximately one minute after the blower post
    purge stops. Control voltage on the TDR is 24 volts from the
    limit circuit. The contacts to supply pump power are 120 VAC.
    They delay on open one minute after the 24 volt control voltage
    is interrupted. Turn off disconnect switch before changing

    If this relay in either case is stuck closed due to a mechanical or other failure keeping the pump running it may be less expensive than replacing the boiler.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System