I have a Rheem RHPL-HM2421JC air handler, a Rheem 1.5 ton heat pump condensing unit, and a comfort control thermostat.
The heat and fan worked well over winter. I can also turn the fan mode to "on" and the fan will run. However, if the system is in cool mode and the fan is set to 'auto', nothing happens. I swapped out the circuit board, but the same problem persist. All the wires in the thermostat seem connected, so i am at a lost for the cause. Any suggestions?