Customer Questions and Answers for Defrost Thermostat (Bi-Metal) by Whirlpool

This defrost thermostat is the temperature limit switch for the evaporator. It lets the defrost heater run when coils are icy and opens as they warm to end the cycle, helping stop frost buildup and restore steady cooling.

• Monitors evaporator temperature; closed when cold to allow the defrost heater to energize
• Opens as the coil warms to terminate defrost and protect components from overheating
• Failure may cause heavy frost on the back wall/evaporator and weak airflow or a warm refrigerator section
• Can also lead to long run times or cooling that returns only briefly after a manual defrost

Includes: One defrost thermostat Install notes:

• Unplug the refrigerator or disconnect power before servicing
• Located behind the freezer's rear panel on the evaporator; remove shelves/ice bin and panel to access
• Reinstall in the same position/clip for firm contact with the coil or tubing
• Make secure, insulated wire connections and route wiring away from sharp edges and moving parts

Troubleshooting tip: At room temperature the thermostat should read open (no continuity); when chilled below freezing, it should read closed (continuity).