Hi.
I'm installing a Honeywell RTH7500D programmable thermostat for a Nordyne Quality Aire multistage heat pump system. Everything looks ok, until I get to a part about Y (yellow), W1 (white), and W2 (black).
The book says system modification is required.
I called a heating/Air person, and he told me that the white wire (W1) should go in the Aux on the new thermostat, Y goes to Y, and W2 doesn't need to be hooked up. However, when I did that, the heat pump doesn't heat (but the fan and compressor are running!) until the temp gets a 3 degree variance, when the Aux kicks in. I'm guessing the W2 wire needs to go somewhere.
Can someone help me?