How do you know the thermistor is ok ???
Outside unit will go into defrost and sometimes won't come out of defrost. Changed the defrost board (no change), thermistor is Ok.
Outside Unit Mod: DRHS0421CB
Inside Unit: Mod: AH16W15BA any ideas?
How do you know the thermistor is ok ???
If it only happans some times, how do you know its not the sensor acting up some times.
is it the type that goes on the discharge line.
Have you tried the Colman -Evcon web site? They have plenty of info on your system