www.hvactechgroup.com - forums

HVAC Forums => HVAC Help => Topic started by: ckavert446 on July 07, 2024, 01:54:28 PM

Title: New to HVAC need some guidance
Post by: ckavert446 on July 07, 2024, 01:54:28 PM
Relatively new to the HVAC trade and have some questions regarding my own residence. Single family, single story house, approx 1300sq ft. Pressures on system seem ok(maybe a little high), delta T also seems ok, but sub cool is high for what condenser is calling for, it's a 410A system. Outdoor temp is around 80F, and we have tstat set to 75. Attached is photos of the pressures and delta T. Thinking there might be something up with the TXV but that's where my knowledge kind of stops. Any help is much appreciated
Title: Re: New to HVAC need some guidance
Post by: samihabib on July 08, 2024, 01:24:12 PM
Check comp amps , if high slightly overcharged ..if TXV system. Your superheat is low ..should be closer to 20 range and your head pressure is high
Title: Re: New to HVAC need some guidance
Post by: ckavert446 on July 08, 2024, 06:44:37 PM
Could the high superheat and head pressure point to an issue with the TXV?

I initially thought I had a leak on my evap coil (I detected with leak detector - have not done an iso test yet) which is what lead to me doing a check up on the system. These readings aren't indicative of a leak are they? 
Title: Re: New to HVAC need some guidance
Post by: Porcupinepuffer on July 10, 2024, 07:56:12 PM
I don't see an issue with a refrigerant leak by those readings. Subcooling tells me it's a bit overcharged. The head pressure doesn't seem to be a problem to me as it's 20 degrees higher than the ambient. The suction pressure may be high from humidity. How long has this been running when these readings were taken?
Title: Re: New to HVAC need some guidance
Post by: ckavert446 on July 10, 2024, 08:53:01 PM
Quote from: Porcupinepuffer on July 10, 2024, 07:56:12 PMI don't see an issue with a refrigerant leak by those readings. Subcooling tells me it's a bit overcharged. The head pressure doesn't seem to be a problem to me as it's 20 degrees higher than the ambient. The suction pressure may be high from humidity. How long has this been running when these readings were taken?

System had been running for 15 minutes or so
Title: Re: New to HVAC need some guidance
Post by: rmuntz on July 11, 2024, 06:36:38 PM
Suction press is high, SH is high, disch press is slightly low.
I'm with Sami, check the amps.
Also, do a compressor valve test.
Title: Re: New to HVAC need some guidance
Post by: tenletters on August 01, 2024, 05:09:23 AM
Quote from: rmuntz on July 11, 2024, 06:36:38 PMSuction press is high, SH is high, disch press is slightly low.
I'm with Sami, check the amps.
Also, do a compressor valve test.

This is probably a scroll. It won't have valves aside from a check valve.