Dryer has started to overheat during operation. Blew thermal fuse twice. Replaced thermal cutoff and hi-temp thermostat. Thermistor seems in tolerance, (does it get lower in resistance as it gets hotter?) Ordered a new thermistor and another thermal fuse. No exhaust restriction, no airflow through felt strips, everything seems to be in working order. The heater element has been changed recently. About 40 ohms through heater coil all the way through hi temp cutoff and hi temp thermostat, and unlimited resistance is noted to ground. I am changing the thermistor on the off chance that it is shifted and commanding the logic on the board to go full high. I think I have checked everything. Any suggestions before I change out the board? Is the heater control Pulse Width Modulated, or just on-off? I could do this all week, but I need to work. The dryer is in great mechanical shape and I will fix it. (I keep having to tell myself this) :rolleyes:
Any suggestions before I change out the board?
By the sound of it you have checked just about everything.
I would check/clean the blower wheel.
Also make sure that it is solid on the motor. Sometimes they can strip but still turn they just do not turn fast enough (slipping).
I am assuming when you say that you have checked the exhaust air flow that you checked the vent system including the louver on the outside of the house.
Check the lint screen sometimes they can get coated with softener residue and have to be cleaned with soap and water.
Is the heater control Pulse Width Modulated, or just on-off?
It is just on-off.