Hi John and list, I pressure tested the system and left the tester on it over night and it only went down 3psi. I pumped it up to 15 PSI and it held there for over and hour so there are no leaks at all. The thermostat is brand new, I purchased it from Grady's last week. Today the fans acted a little bit different. I would hear the relay clicking VERY fast and my "fan fail" light would flicker and then the fans would come on. Any other ideas? I would like to thank everyone who responded. Thanks David