My Whirlpool (bottom) freezer's evaporator keeps frosting, thus rendering the (top) refrigerator warm.
Actions already taken:
- Replaced Defrost heater (U-shaped, stove coil-like heating element)
- Replaced Defrost thermostat (small "eye" looking thing, with 2 wires, and clips on the start of the cooling coil)
- cleaned the coils at the bottom (outside).
- Magnetic door strips looks fine to me.
The freezer frosts completely after around 9-days. The temperature will get extremely cold (-16C) and humidity will be around 70%, with the evaporator completely frosted.
What other things should I check?