Whirlpool Clothes Dryer Thermal Switches

The venerable (circa 1993) Whirlpool clothes dryer (LER443AQ0) that Came With The House™ failed in action: the drum occasionally stopped turning (and, fortunately, heating) while the control timer continued ticking along. The symptoms suggested one of the many thermal switches / thermostats / fuses was bad, but because the problem was intermittent, the only practical alternative was replacing all the things.

Which, it turns out, costs about ten bucks from the usual source. I remain unconvinced paying an order of magnitude more for what look to be identical parts will, in fact, bring either different parts or higher quality.

The wiring diagram, which I consulted only after the fact, shows it was most likely the “Not Resettable” Thermal Fuse in series with the drum motor, because the other contestants are in series with the heater and the Operating Thermostat would trip when the blower stopped blowing:

The fact that the Thermal Fuse should not “reset” after it trips seems worrisome, but failures are like that.

All those parts are accessible only through the rear cover, but you should definitely vacuum out as much fuzz as possible before popping the cover (with vacuum in hand):

Of course, all the old parts show fine continuity, because intermittent:

With the new parts in place, the dryer has chugged through half a dozen loads without incident: so all’s well that ends well.