Personally I think most of them provide a reasonable product. Biggest scam in HVAC is the efficiency issue. No way I'm buying a 99 or 100% efficient heater. They just don't seem to last as long. I don't want better than 85% or worse than 80%. I think that range get's you the best bang for the buck. Make sure you deal with folks who have been in business for a long time. If you don't get the job done, you won't last.
As far as I'm concerned the biggest scam in HVAC is that you always need to replace the heater (or whatever) If they can't replace parts to keep the thing running, in what you have what kind of warranty are they going to provide. Keep them running as long as possible is the song I sing. If they can't do that I don't want to do business with that company. AND, I LET THEM KNOW HOW I FEEL ABOUT IT!!! I don't like a "repair man" to come out and now he's a salesman and doesn't want to do his job.
