I thought that I had finally found an HVAC company I could trust. "Professors of Plumbing and Air" saved me about $1000 last year when I got a second opinion from them. I was so impressed with their service and honesty I even signed up for their "Dean's List" service contract at $67/month which provided twice yearly inspections to my four A/C units and a 15% discount on future services.
I got my first spring inspection a few days ago. When the technician was done and about to leave, I asked him why one of my units was not currently running (I had no prior problems with it). He said it was OK when he checked it earlier. I insisted he recheck it and he told me my compressor was dead and I needed a new one at a cost of $3000! I got a second opinion from another company and it turned out to be a bad capacitor that was replaced for $120! The unit is working just fine now.
Needless to say, I have cancelled my service contract and will no longer do business with "Professor's of Plumbing and Air". The moral of the story is to always, always, always get a second opinion when facing a major expense. The HVAC industry is very untrustworthy.