Air Conditioning - Outside A/C unit wont turn on

I just had a new a/c and furnace put in just over a year ago. Everything was working fine until yesterday. The fan blows, but the outdoor unit just hums. I'm unable to get any help or waranty work from the installer (that's a story for another day).

The fan on the outdoor unit spins in the wind so I no that it's not stuck. I checked the main fuse box to the house, but nothing was tripped there. The thermostat is only a few years old and I put new batteries in it just in case.

Any ideas before I call a repair person?

thanks for the help.

I would turn the breaker in the main panel all the way off then back on. Check the outside disconnect, if its fused may be a bad fuse.

Do you have a meter and know how to use it?

Thanks for your input Dun11. I flipped the fuses on my main box, off then on, and now it works. Just have to keep an eye on it.

thanks again

chris just a note..if you flipped handles on something...those are breakers..not fuses. Fuses either snap in (cartridge style) or screw in (plug style).

Just some terminology clarification....glad its working.

Today I turned on my central A/C for the first time since last summer. The furnace fan works fine but the outside compressor seems to be dead. As suggested, I flicked the A/C circuit breakers on the main panel off and then back on. No luck.

Next to the outdoor unit is a wall-mounted box. There's no obvious shutoff lever, but the lock ring tab for the door moves up and down a bit. I assume that when it fits through the slot in the door it's in the "on" position. Inside the box is a black rectangular plastic insert marked ON OFF. There's no switch but a T-shaped pull handle. Does this hold cartridge fuses? I tried pulling the handle but the unit did not budge and, not knowing what I was doing, I didn't want to yank.

Any explanations and advice? Thanks.

FWIW, the unit is 8 years-old and the manual simply says to call a repairman if it does not work. :wall:

Canadianguy
The box ouside may indeed have fuses..some do, some don't. Normally the off is in one position and it is removed and rotated 180 degrees for on. If it hasn't been removed ever it can take some wiggling and pulling to get it out. Turn the breaker off and try it. There may be a label that says "fused disconnect" or similar.

Thanks Gunguy. The switch was fine. I called a repairman who found that a critter had eaten through one of the low voltage wires. Took him 10 minutes to find and fix it. Would have taken half the time had he not showed me what to look for and how to fix it myself if it happens again. Then he checked the refrigerant, the drain line and some other stuff at the compressor and furnace. Complimented me for keeping the compressor clean and explained why it's important to keep grass clippings and other crud from building up on the sides -- the compresser unit draws in air through the screens on the sides.

Of course the heat wave was over by the time he could come to our place and the A/C hasn't been on since!