I have been in the hvac industry for 17 years but heat pump repairs are not too common for me. I want to be great at what I do but lack experience in this area.
I was called to a one year old Goodman heat pump install that was apparently noisy, gave no heat, and froze up in heat mode. I like to start from scratch so I checked out everything. It is a 5 ton, 2 stage unit but it was only wired as a single stage, the thermostat setting were all wrong, the blower was only moving 1300 cfm, the furnace has return air on right side only(no way you can move 2000 cfm through that), capillary tubes off outdoor txv were rubbing and vibrating so much that they almost made a hole in the tubing. Phew, I think that's most of it. I am trying to be thorough.
It has a piston at the coil but I have not checked the size yet. I had 5 degrees of superheat, with a 57F od ambient and 51F wet bulb. It works well in cooling mode. I switch to heating mode, and it runs for only a few minutes before the outdoor txv freezes up and the compressor shuts off. The condensor fan continues to run so I assume this is the defrost cycle?
I really want to learn so could you please help me understand?