I have a McQuay Type K PTAC Unit that is less than 2 yrs old. When I tried using the AC this summer, the unit would not blow out cold air. The fan turned on but only blew out warm air. An HVAC company came to check out the unit and said the compressor wasn't working. They took the unit for repairs and diagnosed it as a defective expansion valve & weak compressor capacitor, both of which they proceeded to replace. When they brought the unit back to me, the compressor still would not start although they claimed that the unit was working when they had it in the shop. Now they are telling me it's a wiring issue inside the unit.
Am I getting cheated here? Is there any way possible for the unit to be working in the shop but not working when they returned it to my apartment? Can a defective expansion valve or weak capacitor be diagnosed if the compressor was not working in the first place due to a wiring issue? What are some possible causes of a defective expansion valve or weak compressor capacitor?
Any help would be appreciated! Thanks.