I have 2 armstrong heat pumps. One for the upstairs and one for downstairs. They are both about 3-4 years old. The thermostat for the upstairs unit stopped working so I replaced it with a rightemp and a new transformer. The unit upstairs will turn on... but, it heats when the a/c is on and cools when the heat is on? What wire(s) do I need to change?

Thank you
Matt G

Very little fr us to go on. The sense of O/B is reversed. May be programmed by a coonfiguration parameter or may be actual terminals.

I changed it, it still blew out cold air. I changed it back to the original configuration and now nothing will come on. I turned off the breakers while I was changing things. And I have checked the breakers to ensure they are on. There is no fuse for this system. I have tried to jump the red with the green to see if the fan would come on, still nothing. There is no burnt smell from the transformer...

darkevo. So you had heat when calling for cool, and cool when calling for heat, then you changed some wires and it blew cold air, changes some wires again and now it does nothing. Here's my take. Call in a pro before you do any more damage to the systems components. Its going to be hard for us to help from here at this point. I wish you luck in getting it all figured out.

PS. One recommendation. Take the right temp stat outside and see how far you can throw it.

As I said, you didn't give anything to go on like a thermostat model number. You could have blown the transformer again. In the future add a 3 A automotive style fuse on the secondary of the transformer or purchase an energy limiting transformer.

Hopefully you don't have wires shorting in the walls.

Hopefully you set the tstat to operate a heat pump.