I have the same problem as another poster. Just had siding put on home. Now ac has no power. There is electricity powering the unit according to an electrician. Checked all the wires everywhere. When I switch on ac I get NOTHING. (the electrician hard wired carbon monoxide and fire detectors all over the house. Could that have overburdened the breakers?) Im not sure which breaker controls the ac but nothing shows tripped off. Please help heat wave heading my way!!

If you overburdened the breakers they would trip off.

If you have power to the AC unit, try pushing the reset button. It is usually red and located on the AC control panel.

Chuck

What do you mean by "I get nothing"? Nothing inside, nothing outside or nothing inside or outside?

I have an electrician who hard wired fire alarms and CO2 detectors all over the house. He did something to the breaker panel. I am not sure which breaker belongs to the ac. When I turn on the ac thermostat I usually hear the fan (?) turn on immediately. Nothing happens now when I switch it on. It is an American standard thermostat and Amer Standard ac unit about 13 years old. There is no on off switch directly on the outside ac unit. A breaker does not trip. Is it possible the electrician disconnected the connection to the ac? What I mean by I get nothing is... when I turn on the AC from thermostat it doesn't turn on. No sounds no movement completely dead. I appeciate your responses... thank you! Still hot . It will be 95 degrees here today :( Also if the compressor is blown would it make any noise when turned on?? How do I know if it is the compressor?

Does your thermostat have a good battery? Easy to check...
I would hope a qualified electrician could install CO2 and smoke detectors without
Affecting an adjacent circuit but you may need to call another electrician to trouble shoot this one if all the fuses and circuit breakers are good and on...

The original electrician says power is going to unit outside. How would I know if its something else? i.e.. The compressor? If the compressor is blown would it make any noise when turned on? It does nothing. Thanks a lot for your answers! I am trying a new thermostat with new batteries.

Turn the thermostat switch to FAN ON. The inside fan should come on. If not the problem is most likely in the low voltage control wiring. Most units have a fuse inside the unit for the low voltage wiring.

We finally bit the bullet and called an HVAC repair man. It turns out the squirrel that was locked in the attic during home reno went ballistic and chewed up the electrical wire to the AC unit! I knew it had to be electrical. Thank you all who tried to solve my problem. I really appreciate it. It is 90 degrees here and the AC is working great. (after a 300.00 service but definitely worth every penny) Take Care all and THANK YOU AGAIN!