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Wiring a circulator pump

My girlfriends dad wants a thermostat to turn his radiant system on and off. He has a single zone radiant system ran off of a hot water heater. Currently the pump is wired directly to a wall switch that he turns on and off when he wants the system on. He wants to have a thermostat run the system for him so he doesn’t have to do it manually. Is there a way to run the circulator pump with just a thermostat without any separate controls? Or is a separate control needed to power everything.

Comments

  • hot_rod
    hot_rod Member Posts: 22,021
    edited January 2023
    Two options, a line voltage 120 volt thermostat. Or a single zone switching really with a 24 volt stat.

    Lot more thermostat options with 24 volt, and just 2 wire thermostat cable to the thermostat location.

    This relay and most any heat thermostat , a basic tried and true Honeywell.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jaegar21002
    Jaegar21002 Member Posts: 3
    That’s what I figured, the guy who installed the system years ago told him he could wire the thermostat directly to the pump but that never made any sense to me. Also he wanted to reuse an extra thermostat he has but it’s not a heat thermostat, is it possible to use that or is a heat only thermostat required?
  • hot_rod
    hot_rod Member Posts: 22,021
    Is it a heat/ cool thermostat? That would work also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    I am wondering if the switch that currently operates the circulator pump is in a good loctaion for the thermostat. If so, then this would be the easiest thermostat option. All you need to do is to remove the switch and attach the thermostat where the switch is currently located. This thermostat is made to connect the the switch box.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Jaegar21002
    Jaegar21002 Member Posts: 3
    I believe it is a heat/cool thermostat, and the switch is in a different room than what he wants the thermostat in but I will ask. Thanks for all the help.
  • hot_rod
    hot_rod Member Posts: 22,021
    There are wireless stats available also
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    Then you probably do not want to use my idea. You should look into the relay idea at the switch location. You can then run low voltage wiring to a low voltage thermostat in the heated room. You can use a heat/cool thermostat and connect the R and W thermostat terminals to operate the relay. the relay can then operate the circulator pump.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics