As many of you know I have a 2 stage Trane XV80 with a XL16i Heat pump controlled by a Visionpro IAQ. The IAQ controls all 4 stages of heat. I normally run the continous fan all the time. When the IAQ calls for W1 or W2, (aux gas heat), the VS fan will initially ramp up for 2-3 seconds then settles back to the 50% speed continuous fan while the furnace completes it's normal ~30 second start-up routine, then the fan ramps up as it should. I think I remember hearing about the Carrier VS furnaces doing this. Is this a "normal" glitch in the control board?
The fan does not briefly ramp up when there is a call for heatings to the heat pump (Y or Y2) while the fan is running. Only the furnace seems to do this.
Is this something I should care about or just a regular glitch in the system?
I've heard on most systems that the blower should be shut completely off during furnace start-up so the HX can get warmed up quicker so less time is spent cold, where condensation can occur. Should the furnace control board be overiding the cont. fan?
I'd like to know how this particular Trane furnace is "supposed" to operate before I contact my installer to tell them I think there's a minor issue.