Heat pump question: compressor or defrost control?
Parents have an American Standard Heritage 10 heat pump, which they've used pretty sparingly over the last three years (last homeowner installed it around 1998??).
It recently stopped cooling and heating. The first contractor who came by thinks the compressor kicked the bucket. The second contractor who came by thinks the compressor is A-ok and the defrost control board is shot.
Don't know anything about heat pumps but it seems to me that these are pretty different diagnoses!! Is there anyone who might tell me how to figure out who is right?
Many thanks in advance.