[Onelife]

Please help. During the last few days we've had 100+degree days. Our cent air unit shut off n on due to lack of power I assume, now it wont even turn on. since everyone had their ACs on. I flipped the switch and all I hear is this buzzing. Installed fresh batteries in the thermostat. Didnt help.Now I have read similar problems and their solution was changing out the capacitors. I did see that the one person tried to nudge the fan. I also tried but without success.But the contactor relay is whats doing the buzzing. My question is: what do I change to fix the unit ?

 

[Techy]

does the breaker trip?

 

[NJMarine]

Make sure you have correct voltage to the unit and 24 volts at the relay.

 

[heartlessmcfly]

Is your air handler located in the attic? If so, check the drip pan to make sure it is not clogged. If water will not drain, it'll keep the float switch up and won't allow the condenser to kick on

 

[Onelife]

does the breaker trip?

Yeah. As soon as the switch is flipped. But it still hums per say

 

[George6488]

The buzzing / humming sounds like a motor has seized up and is not turning.
With power off.......can you access and spin the air handler by hand?
Again.....confirm all power is shut-off or call in an AC specialist.

I am assuming the sounds are coming from the AC coil area in the attic?


If the sounds are outside by the main unit...........you may have lost compressor, circulation fan, blown a capacitor, etc, etc. Time to call in an expert!

 

[Onelife]

The buzzing / humming sounds like a motor has seized up and is not turning.
With power off.......can you access and spin the air handler by hand?
Again.....confirm all power is shut-off or call in an AC specialist.

I am assuming the sounds are coming from the AC coil area in the attic?


If the sounds are outside by the main unit...........you may have lost compressor, circulation fan, blown a capacitor, etc, etc. Time to call in an expert!

No. Theres nothing in the attic. The unit is an outside Rheem classic. Lines go through the wall into the furnace. The humming is coming out of the unit itself. With the external panel off you can see where the wires connect to the capacitor, contactor relay etc... But the sound is coming straight from the contactor relay. Which confuses me because it has no moving parts. Any ideas ?