Hey people - I'm having a problem with my A/C unit. Pretty new unit and the thermostat checks out fine as it worked fine on my other A/C unit - it was the thermostat given with unit and I haven't messed with any of the wiring.

Here is the deal - the heat will turn on (gas) and the fan will run. I can set the fan to on and it runs fine. When I set to A/C - nothing happens. No fan, no outside compressor, and no little "click" sound that turns on either.

Is it the relay?

Look at the first thread on this board in ref to the terminals. If the stat has an Rh and Rc and there is only one R wire to the stat the two terminals need to be jumped. Also at the unit make sure one low voltage wire from the outside unit is on C and the other is on the Y terminal along with the same color from the stat also on the Y terminal.