OK, maybe not all HVAC contractors are arrogant. There are certainly many that I have not yet met. The non-arrogant, presumably like you, must reside in that camp.

And even (most) plumbers understand the concept of gravity.

I receive calls from tradesmen of all sorts each week wanting to argue about issues in my reports. Surly, know-it-all assholes that cannot seem to come to grips with the fact that they would not be there, reading my report, and collecting a check if I had not referred the client to a trade "professional".

I registered on their forum and look forward to learning something. I'm not itching for, but will certainly not back down from a fight, should one ensue there.

Aaron