Hi,

We just replaced our thermostat. Seemed simple enough -- 4 wires, red, white, yellow, green. There is 24 V between red and all the others at the thermostat. When we set the temp to cool, you can hear the switch in the thermostat click, but no air comes out. It seems like the thermostat thinks it's cooling, but the air conditioner won't get with the program. The a/c was working with the old thermostat (it's just that the down arrow key was broken, otherwise seemed like everything worked).

We flipped all the breakers in the breaker box before installing and then turned them all back on once it was in. I've read that there are fuses and stuff we should check, but didn't immediately see any near the outside a/c unit. We're new to this, so any advice you can give on where to find all of these fuses and breakers would be great.

Thanks!

An

Sounds as if you did everything right and took all the correct measures. Possible the new stat is bad. If you have a continuity tester, take all the wires back off, test across the red and each other wire. You should see continutity between red and white in heat mode, again between red and yellow in cooling, and red and green in fan only mode.

I assume you put the old stat back. To test your system, short out each set of wires I just described, and each system should start up,
Red-white=Heat
Red-Yellow=cooling
Red-green= fan

Thanks for the info! We'll try that. We didn't put the old thermostat back yet as we're not living in the house at the moment.

We thought this was going to be a simple little project, but I'm beginning to wonder if there is such a thing!