AC Problem, looking for troubleshooting help before I'm able to call someone.

[th3w01f]

We have two ACs at the house, both are identical Carrier's and were installed in 2011. The one on the lower level stopped working today, it appeared to be working earlier but the lower level has slowly climbed from 74 to 77 now while the upstairs is maintaining 74 no problem. We have never had an issue before so they are properly sized. I checked the units and both have the fan blowing and look to be working identically, there is no ice build up and I'm not seeing any obvious issues.

Filter was recently changed (about two weeks ago) and isn't an overly restrictive (expensive) filter.

Anything I can check before having to call someone out?

[OtterbatHellcat]

Email Highclass Whitetrash.

He's the shit, when it comes to that stuff. Bad ass and stuff...

[Wulf202]

Touch the large copper line coming out of the condensor. It should be cold and the small one hot. If not the compressor is unlikely to be running.

Are they on seperate t stats?

Are you comfortable with basic electrical?

[Wulf202]

Need to check the contact and see if its pulled in. If not trouble shoot low voltage side. If yes verify power going thru the contactor. Then check the capacitor. Then check the compressor.

[th3w01f]

Thanks for the advice but the electrical troubleshooting was over my head. Had the pros come by and it was low on 410A, no obvious sign of a leak but it's twin was fine so they're going to check it again in a couple weeks for no charge.

[jslo]

Make sure the caps where you evacuate and charge the system are on, see them missing a lot, and the needle valves can have a very slow leak

[bryjcom]

Thanks for the advice but the electrical troubleshooting was over my head. Had the pros come by and it was low on 410A, no obvious sign of a leak but it's twin was fine so they're going to check it again in a couple weeks for no charge.

Will guaran-damn-tee you that the coil is leaking. Not going to find it in the normal solder joints. Going to find it in the middle of the coil. Coil should be under warranty, will just have to pay labor. Found out this summer that the carrier coils had some problems with them leaking and also the TXV getting stuck.

The coil model # should start with a "CNPVP"

It will leak again..... Unless they mis-diagnosed it and its actually a TXV, which will stick again.