When should the blower activate, before or after opr'l temp?
A Lennox Series gas furnace w/ heatpump Model (80 MGF3/4-100, 12HPB036, C26-41) was installed at the time I had the home built. Things appeared correct in the Furnas assembly as to the sequence of operations, but I did concede I was unfamiliar with how the sequence of events of the heating and cooling via the various sources should interact. I did notice in ALL modes the FAN was the first thing to operate... I thought this was somewhat strange because it can produce an uncomfortable environment for a few minutes prior to actually performing the required function. If you need heat, the FAN and Heatpump operate simultaneously and immediately (The Compressor operates in reverse of what it does for the cooling function producing heat in the "A" frame coil (inside) assembly instead of the condenser coil (outside) assy.)... However, this also leads to an uncomfortable environment until the "A" frame coil assy begins producing heat. The older/earlier furnaces have a temp switch that keeps the FAN in the OFF mode until the actual heat source comes too temperature and then the temp switch turns ON the fan. This unit has temp switches but don't appear to be wired to operate the system in this manner. To further complicate matters a NEW heatpump assy was installed after a lightning strike but, ONLY the cooling function operates (TX Valve jammed, long story) of which requires a continual operation in "Emergency Heat(EH)" mode to heat the home. EH consists of natural gas backup of which is more expensive than pulling heat out of the air. And again the FAN is the first and ONLY thing that immediately comes on. It’s a good full minute or two of COLD air before the gas fired heat exchanger begins producing heat. Now the question, (Finally! You say!). IS this Assembly working properly? It seems the FAN should come ON after the heat sources have come to, or near there operational temperature or is this the way they achieve efficiency?