On 2015-05-03, Ed Pawlowski wrote:
On 5/3/2015 6:07 PM, Ignoramus18130 wrote:
My home A/C was turned on yesterday, and we realized that it blows
warm air instead of cold. I did a little bit of investigation and also
changed the filter.

* The outside unit fan is running, but the compressor itself
seems to be not running. I measured amps going to it, it is about
1.4 amps 220v, consistent with only the fan running.

* The cold refrigerant line (with thermal insulation) is not actually
cold but warm.

* I just changed a filter. The evaporator coil was not easy to see so
I did not look at it.

Would you have any troubleshooting suggestions. The outside unit is
relatively new. Thanks


A few possibilities. Low refrigerant, bad capacitor, bad relay. Do
you have the ability to check that stuff? If not, time to call a pro.
Best to call now instead of July when it is 105 degrees.

Guys, thanks a lot for your help.

I have a business buying and selling industrial parts and doing some
industrial scrap metal. So I think that I can troubleshoot this. I do
not have any experience working with refrigerant.

My understanding is, the compressor has a single phase motor with
external capacitor and resettable overload relay, right?

So, I would check, first, if there is 220v coming in (there likely is
since the fan runs), secondly whether there is 24v coming into the
coil of the contactor. If yes, I would check the overload relay. Maybe
after this, turn off the system for 30 minutes and turn it back on to
see if there is any humming or running compressor motor.

Then I should have a good idea if the problem is in the boards, power
coming in, relays, or capacitor, right?

i