Frigidaire FPRH19D7LF1 (2014) standalone refrig not chilling below 40-42

[dawg11]

Model Number

FPRH19D7LF1

Brand

Frigidaire

Age

6-10 years

Right at 1 year ago, we had the freezing of items problem I've seen about this unit. I replaced the thermistor. Initially I believe I had a couple of more freezing sessions (so I thought problem still there) but the freezing stopped and refrig has been left at 34 setting. The thermometer I put in there was reading around lower 30's to near 40 depending on when I looked but everything was always good and cold (since last Sept). Now, the last 5 days, it won't go below 40-42. I even tried 33 on the setting to no avail. I see there is another thread on a similar unit, the FPRU19F8FR. I think it might close to the same model/parts.
Do I need to remove back panel inside refrig and look for partial frost like described in that thread? If I see partial frost, does that indicate freon leak? If so, could a valve be brazed in, system vacuumed, and then re-add 134a to appropriate pressure? If I do not see partial frost, check thermistor reading? Could control board be involved? This is a built-in look with a matching freezer. I cannot imagine having to replace it/them. Any help is appreciated.

 

[rickgburton]

Make sure the condensor is clean and both fans are working first. When you check the frost pattern leave the machine plugged in and running. A partial frost pattern indicates a problem in the sealed system. A refrigerant leak is only one possibility.

 

[dawg11]

So I have a partial frost pattern. The pipes and fins on left have frost. Is freon leak most probable cause? Anything else I should check? I was thinking I would try a BVP31 piercing valve (I assume I don't have a port but haven't looked - going to a pain to pull out) and check low side pressure and add 134a if necessary. This sound reasonable? I suppose everything should be running when I check charge? Should it be 10-15psi? Looking for at least a temporary fix.

 

[rickgburton]

Yes, that's a sealed system problem. It's either a leak. restriction or inefficient compressor. There are no service valves on that machine.

 

[dawg11]

Ok. Should I be getting 10-15psi on low side when I check it? I saw some testing of compressors using ohm meter on youtube. Is that what I should do to test the compressor efficiency? Could a bad defroster cause this or would the frost be more uniform?

 

[rickgburton]

Should I be getting 10-15psi on low side

No, not even close. Sealed system repairs are best left to the pros. I can't teach sealed system repairs online. The last time I helped someone with a SSR it took up way too much of my time. Over two months and like 100 posts. There's too many variables and some things you just can't teach online. Sorry