I have been working on a 2 ton trane system, installed in '01, 410a unit, and cant seem to get it right.
I went out first call, found head press low, suction press low. added freon, couldnt get pressures to increase no matter how much i added.
Checked evap coil with camera, nice shiney clean, pulled blower to check secondary xchanger, shiney clean, blower clean. Cleaned condenser coil.
No change in operation. Figured TXV sticking open. Replaced TXV. Vac. down to 400 microns, holding good. Open system up & run. Running great, charged to 12 deg. subcool. Dropped house temp from 78 to 75 in about an hour. Good to go.
Calls back later that day, not keeping up. Go out start unit, head press up to 450. Recover some freon, down to like 300 psi running press. Run system, check things over while running, like clogged drain trap, check temp drop across coil, 77 deg. r.a., 55 deg supply side. End up adding small amount of freon to get to 12 deg SC. House cooling down good. Call last nite, not working, 80 deg in house. I guess what i'm wondering is after a couple hours of running, could the compressor be getting hot and bypassing gas or something?? Did not do an amp draw, but will today. More less hoping typing this out would make me think of something i missed.
When i left yesterday this is what i had
Indoor temp - 79
outdoor temp - 83
Head press - 295
Suct. press - 125
subcool - 12- 14 deg
22 deg drop across coil
No evidence of water around furnace, and H.O. says blowing good at reg's., so its not icing up.
Any ideas are appreciated.