Location of thermostat low voltage.

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Belltfrank
Belltfrank Posts: 3
in Thermostats and Controls

How can you find the low voltage source to a thermostat that powers several  wall heaters. No central system just the thermostat and the heaters. I am thinking maybe the same transformer as the door bell but that works. 1982 home. I replaced the mercury thermostat but still not working.

Thanks Frank

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Posts: 21,328

    If the thermostat is low voltage there is a transformer somewhere unless the equipment is a POWER PILE system where voltage is generated by the gas flame.

    Is it several wall heaters with one thermostat? If so, look in each heater. I assume that there is 120 volt in the heaters to run the fans.

    If the transformer is in the basement, then look (usually) around the breaker panels

  • HomerJSmith
    HomerJSmith Posts: 2,837

    What kind of heating sys do you have? Electric baseboards are different than hot water baseboards, etc.

    Belltfrank
  • bburd
    bburd Posts: 1,338

    Low-voltage HVAC control transformers are 24 V. Doorbells are 16 V. They are not interchangeable, and I've never seen one transformer used for both purposes.

    —
    Bburd
  • Jamie Hall
    Jamie Hall Posts: 27,975

    First problem is that you replaced the mercury thermostat. If it wasn't actually broken, it was superior to any other non-smart thermostat you could bu — at any price.

    But what's done is done.

    Now the next point is that a simple thermostat — like the mercury one you junked — is just a switch. It does not need a power source. It is possible the the device it controls needs a power source to operate — most do — but all the thermostat does is close a circuit. The controlled device is where the transformer would be — if there is one. If a single thermostat is controlling several devices, there may be relays taking the thermostat signal to transmit the call for heat on to the devices — in which case there would be a transformer. probably near the relay, to power the relay.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England

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