Could you please assist me in understanding how the XV80 is supposed to work in the heat mode. I have a 2.5 ton x19i condenser, XV80 model TUD080R9V3K (gas), and the TN803 thermostat. In the cooling mode, the Comfort R is brilliant, operates at a very low speed most of the time --- a truly variable speed fan, no noise whatsoever.
In the heat mode (dip switches set for low airflow setting), the fan speed appears to work just in two speeds: low (Stage 1 heat) and high (Stage 2 heat). The speed in Stage 1 heat appears to be as high as that of the cooling cycle in Stage 2. The speed in Stage 2 of Heat is really annoying noise-wise.
Should I assume that the heat cycle has no fan speed variabilty built into it to keep the air flowing relatively fast so that the heat exchanger does not get fried. Or is there anything messed up with the furnance fan speed issues?
Any suggestions for mitigating the noise issue?
Thanks - JR