I have a whirlpool 27(kenmore) dryer that's 9 years old. It has recently stopped heating consistently, but it will heat sometimes though. I've cleaned out the inside of the dryer and exhaust duct thouroughly(it was very "linty"). I've also tested the reistance of the heater coil and the 2 sensors connected to the heater housing, all are fine. I also tested the thermal cutoff on the exhaust housing(of course it's fine since the dryer still runs) and the thermistor. All appear to function properly, so it must be either the heater relay, the electronic control board or possibly the centrifugal switch on the motor. Does anyuone know if the dryer would still heat intermittently if one of these 3 parts was bad? Thanks for your advice!

FYI to anyone having the same problem, I replaced the heater relay for ~$40 and fixed the heat on the dryer. It's easy to diagnose, I found. Just use a multimeter to test the voltage on the relay(instructions are on the tech sheet inside the top housing.) The No and COM(red wires) should read 0. Mine read over 200 so the relay was the problem. Hope this helps anyone having the same problem.