My a/c in my home was working perfectly. I bought a new electronic honeywell thermosatat last year. I went and bought new batteries today and changed them because I thought they needed it. That was stupid!! I changed the batteries and now me unit will not turn back on. Everything looks to be working perfectly on the thermostat, but the a/c will not come on. The Fan will not even turn on when I switch it to fan. I have it on Auto and cool now but it has been 30 minutes and nothing! Can you offer any help?

Kelly

Is it a battery only thermostat?

Usually just changing the batterys will not cause a problem.

One thing you might try. Turn off the power to the indoor unit wait a minute and turn back on. That might cause a reset.

Yes it is just a battery only thermostat. We have tripped all the breakers and reset them all, and everything else I can think of. I am lost with this thing

Interesting. Are the battery's put in correctly? I am sure they are but you might check. Unless a wire came off the thermostat while you were changing the batterys I can see no other solution but the thermostat may have gone bad. Strange circumstances.