Steve@Advance
Well-known Member
Looked at a coworker's home AC unit this evening. It's a 3 ton, R22, older system with orifice tubes, the condenser unit has been replaced with a newer scroll compressor.
This system has a history of a slow leak. In the past it has worked well when fully charged. I had the evaporator out 2 years ago repairing a condensate leak, and the coils were cleaned then.
Yesterday he asked if I could add some refrigerant, it wasn't cooling properly.
Went by this evening and it was about 80 in the house, blowing cool but not cold air. The return line was sweaty cold back to the compressor. Put the gauges on, 90PSI on the low, 300 high. It was about 97* outside. I told him it didn't need refrigerant, he wanted me to put some in anyway, so I did just to see, but it did nothing but raise the high to 320PSI.
The air coming off the condenser coil is barely warm and the compressor is very quiet, like it's not working quite as hard as it should. I turned the unit off for a few minutes, let it unload pressure, and when I turned it back on the compressor sounded like it was pumping as it should (already had the gauges off), then in about 3 seconds something sounded like a pressure relief valve popped off, making a hissing sound that somewhat diminished but continued to hiss. Whatever it is is internal, nothing was escaping. BTW, this is a straight AC, no heat pump.
Any ideas what is going on?
This system has a history of a slow leak. In the past it has worked well when fully charged. I had the evaporator out 2 years ago repairing a condensate leak, and the coils were cleaned then.
Yesterday he asked if I could add some refrigerant, it wasn't cooling properly.
Went by this evening and it was about 80 in the house, blowing cool but not cold air. The return line was sweaty cold back to the compressor. Put the gauges on, 90PSI on the low, 300 high. It was about 97* outside. I told him it didn't need refrigerant, he wanted me to put some in anyway, so I did just to see, but it did nothing but raise the high to 320PSI.
The air coming off the condenser coil is barely warm and the compressor is very quiet, like it's not working quite as hard as it should. I turned the unit off for a few minutes, let it unload pressure, and when I turned it back on the compressor sounded like it was pumping as it should (already had the gauges off), then in about 3 seconds something sounded like a pressure relief valve popped off, making a hissing sound that somewhat diminished but continued to hiss. Whatever it is is internal, nothing was escaping. BTW, this is a straight AC, no heat pump.
Any ideas what is going on?