Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have an American Standard heat pump AC. I'm replacing a White-Rodgers manual thermostat (where I move a switch from cold to heat) with a Honeywell RTH7600 (which will automatically switch from cold to heat).

When I take off the old thermostat, I have a red wire (power) that will go to the Rc with a built in jumper. I have a green wire (fan) that will go to the G. I have an O wire that will go to the O/B.

My problems lies with the yellow wire. My yellow goes to the Y and also to a W. If I'm reading my manual correctly, I think I can put the yellow wire only to the Y since the new Programable thermostat automatically switches from cold to heat.

Is my thinking correct?

share|improve this question

enter image description here

See below, if you jumper Yellow to White the heat strips will run in both cool and heat as Yellow is energized in both modes, what makes it a cooler or heater is the O being energized in cool mode Rheems use the B terminals to be energized in heat.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.