Skeptical HVAC Issues
I am looking for some advice for an HVAC issue that I have been having at one of my rental properties. I am pretty well educated on the nomenclature and process for A/C systems, but am not up to speed on pricing and proper diagnostics.
My tenant told me in August that the A/C was freezing at the condenser, at which point I had contractor #1 take a look at it. He replaced the transformer/capacitor and added 1.2 lbs of R-22. A/C worked for a week and the problem recurred. Got a refund because the "repair" failed.
Contractor #2 found that the R-22 was a little low and added 1 lb, but saw no evidence of leaking. The A/C worked for about 2 weeks, but the system stopped outputting cool air.
Contractor #3 had fluctuations on his gauge so he sensed a leak or a bad metering device. He seemed very knowledgeable and I decided he�d be best suited to perform a leak check on my system. He performed a triple evacuation of the refrigerant to 500 microns and checked for leaks/noncondensables.
There were not leaks discovered and he recharged the system. This worked for about a month.
He had a tech come over and diagnose the system again. This time they replaced the capacitor because it was reading low. No fix, but we are having a different problem, and I am ready to ditch this guy all together. Here is what contractor #3 says in an email:
"I just got a call from the distributor. They had to look up your coil info with the factory since its not made any more..it looks like that coil didn't come with a TXV..and for it to behave the way it is means basically that we caught the air in the refrigerant lines too late.
We may be able to replace the coil and flush the refrigerant lines...but if the compressor was too damaged and has shavings breaking off into the lines that may need to be replaced too. It was suggested that we perform an acid test and megohm the compressor to try and determine AC longevity since the system is a bit undersized"
After telling him that only the fan was working(blowing ambient air and not cool air at all), this is what he said:
"When I first put my gauges on yesterday it was acting low on charge..then it acted like a Txv open and everything went normal for an hour or so. Then before I called you it seemed as a valve had closed causing really low suction pressure and high head pressure @ the same time.
I had told him to not use the AC and run fan only or set stat to ac and kill Pwr to AC unit for full fan speed ti prevent further damage.
I live in a house where my system is 3/4 ton undersized..for now it work ok...but when it starts giving me problems I'm just going to replace it all with high efficiency stuff properly sized.
I know were looking @ at least replacing the coil...possibly the compressor or condenser. It may be a good time to upgrade the system but that would require increasing the cfm by doing the furnace @ the same time. And that's your call. @ this point no matter the choice..we have to evacuate the refrigerants again. But if you upgrade the system we can credit the work we've already done to help out a bit.
Sorry for the novel, but I really would like some input from the community. I have the feeling that contractor #3 is trying the old "hook-line-and �sinker" method with trying to get me to pay for a complete system.
Any thoughts? Thanks in advance!