Maytag Refrigerator PBB2255GEW Freezer not defrosting

The Defrost Thermostat Kit is an OEM part for Whirlpool refrigerators. It regulates the temperature in the freezer during the defrost cycle, ensuring that the defrost heater activates to melt any frost buildup and then turns off to maintain the proper freezer temperature. This thermostat opens at 42°F and closes at 30°F. This mechanism allows for short, controlled heating periods to melt frost without affecting the contents of the appliance.

You should replace this defrost thermostat kit if it becomes defective. Common causes of a bad defrost thermostat include electrical failures, prolonged exposure to extreme temperatures, or wear and tear over time.

Symptoms of a bad defrost thermostat include:

• Frost buildup in the freezer
• The refrigerator running continuously without cycling off
• The freezer not maintaining the correct temperature
• Water leaks from the freezer during the defrost cycle

This OEM part is also compatible with Maytag, KitchenAid, Jenn-Air, Amana, Magic Chef, Admiral, Norge, Roper, and Kenmore models.

This refrigerator defrost timer automatically starts and ends the defrost cycle to melt frost from the evaporator coils. Replacing a failed timer restores consistent cooling performance and helps prevent frost buildup that can restrict airflow.

• Controls the timed switch between cooling and defrost to keep evaporator coils clear of frost
• Common symptoms of failure: heavy frost on the evaporator or back panel, fresh food section too warm, unit runs constantly, or won't resume cooling after defrost
• Restores proper frost removal and airflow for stable temperatures
• Designed to match the original timer's function and wiring connections for applicable models

• Disconnect power before servicing; wear cut-resistant gloves
• Access location varies by model—often in the fresh food control housing or rear machine compartment
• Photograph/label wire positions and transfer them to the matching terminals on the new timer
• Reuse original mounting hardware and install in the same orientation as the original

This evaporator defrost heater melts frost from the freezer's evaporator coil during the automatic defrost cycle, restoring proper airflow and cooling. Replacing a failed heater helps prevent recurring ice buildup and temperature swings.

• Heats the evaporator coil at set intervals to clear ice
• Maintains airflow so the fresh food section and freezer cool consistently
• Common signs of failure: heavy frost on the back freezer panel or evaporator
• Other symptoms may include warm refrigerator temperatures, reduced airflow, or fan noise from ice contact

• Disconnect power before servicing; wear appropriate PPE
• Access the heater behind the freezer's rear panel; defrost ice with warm air/steam—avoid sharp tools
• Reinstall in the original position; keep wiring clear of the fan and moving/hot parts; ensure secure harness connections
• After reassembly, verify the defrost cycle per service instructions; if frost returns, also check the defrost thermostat/bi-metal and control