Fan motor cycles even when the controller is set to run constant. The motor was replaced by a service company about 30 days ago while I was out of town. Since I have been I have been noticing the fan cycling. I have been in this house for 10 years and the unit is a comfortmaker high efficient unit. We have been running the fan constantly for all the ten years and once a year I reoil the motor. If the fan is set to run constant why would it cycle???
As it turned out the AUX blower fan in the long vent was trying to burn up. That was the noise we were hearing that made us think the main blower fan was cycling. I turned off that fan and will obtain a new one sometime today.