My central a/c won't power on. I checked brakers, etc. Any ideas??

Question

Unit is a 3-ton trane, 4 yrs. old.

I live in S. FL, so it's plenty hot. I did flip all the breakers off, then on. I can hear the thermostat click when I adjust the temp., like it's doing its part. As a coincidence, for the first time since the a/c was new, I have a renter in the house for the last month. Is there any way they could have messed it ?up?

Answer 1

Edit the Question, Fan inside coming on? etc... more info and im sure we can give our $02

Answer 2

It could be any one of a number of things. The breaker in the panel could not be fully engaged. The "disconnect" on the side of the house near the A/C could be in the "OFF" position or if it is a fused disconnect, one of the fuses, or both, could be blown. One of the low-volt t-stat wires might have come undone inside the furnace or inside the a/c unit. The best way to check the low-volt wires is to turn the t-stat to cool and then check the air conditioner to see if the contact pulled in. In order to do this, you will have to remove the cover from the a/c, and look at the contact (the black thing where the 220 wires from the disconnect are hooked up). In the center of the black thing (relay) is a little square button (the contact) and if it is pulled in it will be pulled down below the edge of the relay. If not, it will be flush. If it is pulled in and the unit isn't coming on then either the fan motor has gone out, the compressor has gone bad, or the capacitor is blown and you better call a service tech.

Answer 3

If as you said,breakers, thermostat, frozen lines have been checked and all seem OK it could be the CONTACTS in the unit especially if there has been a thunderstorm lately. As some of the advise offered has said be sure to throw the breakers all the way off then back on as they appear not to be tripped sometimes. Also before checking the contacts be sure to disable the electricity. Good Luck

Answer 4

You may have short cycled it. Turn off the circuit breaker for 5 minutes and try it again. If no go call a repair man after checking the system for a broken wire if u know how.

Answer 5

If the breakers are normal and not tripped. You are probly low on freon and the lines have frozen go to you outside unit and check the lines to see if they are frozen. if yes, let them defrost on their own to get you going again. Then, call the A/C company and have your unit serviced. Worse case scenario: The compressor has failed, 3 ton unit approx. 250-300 dollars repair and replace. again depends on where you live. ggroes also has a good idea.

Answer 6

usually there are 2 fuses in an external fuse box on the side of your house near the fan unit. This fall mine blew one of these fuses. the internal breakers in the house were good and the thermastat was kicking in but no fan and no AC. I changed both fuses for under $15.00 and was back in business. I would have it checked after you get it running again but not an emergency call.

Answer 7

Did you check each individual breaker by flipping it off and on? Sometimes when a breaker trips, the switch remains in the on position.

Answer 8

Some units have a reset on the printed circuit board on outdoor unit.

Answer 9

check power to the disconnect near your unit ( outside). got power there? have technician check compressor for electrical short. thats a new unit, shouldnt be compressor. thermostat ok??
call for service.

Answer 10

Check the fuses and wires in the outside box.