My old unit died and had a new unit installed. Different brand than what I had before. The installer has it set for the aux heat not kick in, only if I go to the emergency heat setting. I was told before, at least with my old geo that it isn't a good idea to disable the aux. If the unit is calling for aux heat, it means it can't keep up without it. Is this true? Also, the closed loop has 2 pumps, one on the inlet and one going out. Each pump has a switch for speeds, low, med, hi. Both are set to med. I didn't get a explanation on what the settings are for or if they would ever need to be changed. What is the reason for different speeds? My old unit just had one pump on the loop.