What are the characterists of this refrigerator when the defrost heating coils go out in a high humidity area? The bottom freezer grows ice on the back wall (upper frig gets warm) and the coils seem to be frozen. I can defrost using a hair dryer, water pours into the pan, and the unit works fine again for another 5-7 days. The defrost drain pan was dry today when it frosted over again. Unplug and a quick hair dryer attack, and all is well again. I can order parts from this company, but I am not sure this is the problem. Model mfg 10-2002.

Thank you for taking your time to offer suggestions. We need a service repair manual and your answer helped. My husband will attempt your suggestions this weekend. We live on the ocean and the humidity seems to trigger this issue last summer and this summer, too. It NEVER happens when we can get the service company here to see the problem - so we have attempted to handle it ourselves. The hair dryer approach works "temporarily" but is not the fix or solution.

Correction: Not Maytag bottom freezer - GE Profile PDS22LBNWW
Defrost Thermostat Bi-Metal is called Thermostat Kit which should appeat in diagram #4 (but is not shown) and listed as Item #29: Thermostat Kit, AP4009073.