I own a Kenmore refrigerator, made in yr.2000, and have been trying to resolve an ice build-up problem in the top freezer compartment which eventually leads to water dripping into the fridge compartment through the air flow vents. I replaced the defrost timer and the problem continued. I took a continuity test of the heater element and it checked out fine. Today I replaced the "DEFROST THERMOSTAT" and thought I could test it by manually turning the timer by hand to the defrost cycle (fan shuts off when I do this) and the heating element would get warm/hot but it didn't.

HERE'S MY QUESTION: Does the newly installed thermostat have to be at a certain temperature in order to function properly? It was at room temp when I first installed it.

Any advice/guidance/suggestions would be appreciated... greatly
Thanks,
Jimbo

The thermostat determines when the defrost cycle terminates.

The defrost timer basically "suggests" when the unit goes into defrost. It's basically an percentage timer. An off time followed by an on time. The compressor turns off and the defrost heater turns on until the temp is slightly above freezing. Then when the defrost time is up, the compressor is allowed to run again.

Check for gasket failure and also do a complete manual defrost to defrost any internal passages.