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Minneapolis Honeywell Temperature Regulator

We have an old Capital Heater Boiler with a Minneapolis Honeywell temperature regulator valve motor on top. I am interested if anyone has a maintenance manual for this unit:-)

Much Appreciated
William Higinbotham, Bellport, NY


  • STEVEusaPASTEVEusaPA Member Posts: 4,737
    You might need a time machine. What does it do? If I had to guess, I would say it opens/closes valves on the supply & return to try to control the temperature of the gravity flow?
    What does it look like under the cover? What problem are you having?
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 8,071
    Don't mean to be harsh but I think your ready for some new equipment.

    What's with the oil line circling the boiler? That is a danger getting stepped on and causing an oil flood.

    I doubt you will be able to find a manual....but it's possible
  • JUGHNEJUGHNE Member Posts: 7,901
    It looks like a double shaft motorized zone valve with a gate in each hot water supply riser. Really neat actually. Some one would want it as a collectible.

    But I also would suggest the whole system has done its duty by now.
  • JUGHNEJUGHNE Member Posts: 7,901
    If the motor has failed you can manually open the valves as indicated on the face.
  • HVACNUTHVACNUT Member Posts: 3,707
    edited November 2017
    I think the manual for that control is under the boiler. You can get to it after you haul that beast out on a hand truck.

    That looks like a pretty cool control though. Looks like its controlled by an old series 3 thermostat. Power open/power close for the valve.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 8,071
    120 volt power in the bottom. 3 wire series 10 Honeywell thermostat control. I am guessing they used it for DHW and the thermostat drove the valves shut in the summer to prevent heat upstairs. Pretty neat. never saw that done before
  • whiginbothamwhiginbotham Member Posts: 2
    edited November 2017
    The three wires come from the Honeywell T-87 mercury type thermostat. The issue is that the valve opens OK, but when the thermostat opens (close valve command), the motor runs constantly, does not stop. We can control the motor manually with the front control (Thermostat disconnected). We think a sensor switch inside may have failed. This is why I would like to get a copy of the manual. This is a heat convection type system.
  • John Mills_5John Mills_5 Member Posts: 935
    Frosty the Snowman...

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