Frickin' Fridge Followup
It's been about a week and a half since we had out Kenmore refrigerator serviced by Sears, and I'm happy to report we haven't had any further trouble with it. The fridge defrosts normally now -- the circulation fan actually shuts off and the system actually warms up enough to melt the frost that forms, which we don't see, but you can hear it dripping down the drain tube every so often.
I had shut off the water supply to the ice maker when this problem started, thinking that perhaps a slow leak in that system was contributing to the influx of frost. So once the defrost circuit was replaced I turned it back on.
It's a simple creature comfort, but I really love not having to manually fill ice cube trays to get a cold drink. Watching food not spoil is good too.