Do I have a single or multi-stage heat pump? Want programmable thermostat.

hvac1000 · Oct 9, 2007, 12:13 PM

You have a two stage heat one stage cool unit. First stage heat is heat pump second stage is resistant heat.The wiring colors will be explained in your new thermostats install instructions. Honeywell makes a good thermostat. Please read the entire manual that comes with your thermostat. If that fails you then look to the sticky notes at the beginning of this board.

acetc · Oct 9, 2007, 06:14 PM

I disagree, it appears you have a three stage heat, the first stage is the heat pump which is the orange wire that reverses the reversing valve, the W-1 is aux. (electric heat strip), the W-2 is another aux. Heat strip, that makes three stages of heat.
The second heat strip may be connected to an outside thermostat to keep it from operating until the temperature drops to a preset temperature, this saves money.
The "G" is to engage the indoor fan, the "Y" is to bring on the compressor, the "C" is the common from the transformer to operate a clock or lites in the thermostat, the red "R" is from the transformer (a different leg from the "C") this is switched by the thermostat to the G, why,W-1,O, W-2, depending on what is desired by the operator.
The "E" is emergency heat and when switched on it disables the heat pump and only enables the aux. Heat.

blueruler · Oct 9, 2007, 10:22 PM

Thank you both for your answers. Is there any further information I can provide that would give me a definitive answer? I have pictures of the thermostat, and of the wiring diagram from the inside of the cover of the heat pump unit if either would help.

Thanks again for your time.

Do I have a single or multi-stage heat pump? Want programmable thermostat.

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