Thermostat question. Load on the stat when the furnce is on?

Discussion in 'Heating / Cooling Systems' started by Spridle, Oct 13, 2019.

  1. Spridle

    Spridle Active Member

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    I'm sure this is out there, but a quick search didn't give me what I wanted. Anyone know the actual draw on the stat when the furnace is running? I'm going to experiment with something different than the basic mechanical stat. And I'm assuming I'll need a relay to make it all happen. But the unit I'm going to play with first does have a simple pass through and may be able to handle the 12v, if the draw is not too high. Thanks in advance.
     
  2. NMroamer

    NMroamer Well-Known Member

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    The thermostat is a simple switch that turns on the 24volt transformer. Minimum current draw.
    Guessing 5amps or less.
     
  3. Raycfe

    Raycfe Waterford Ct.

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    There is no transformer, just a 12 volt relay.
    The thermostat is just 2 wires. A simple digital one works so much better. Use the R and W terminals.
     
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  4. Spridle

    Spridle Active Member

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    Is it using a 24v transformer internally? Pretty sure the furnace doesn't draw more than about 3A total, although that my have been my old 12K unit. Regardless, I'm assuming we are talking like .01 amp draw here. Worse case, I'll measure it.
     

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