Refrigerator Runs Constantly and Won't Stop: What's Wrong?

While refrigerators are designed to run frequently to maintain proper temperatures, a unit that runs constantly without cycling off indicates a problem that needs attention.

Dirty condenser coils are the most common cause. These coils release heat from the refrigeration process. When covered with dust, pet hair, or kitchen grease, they can't dissipate heat efficiently, forcing the compressor to run continuously.

In Arizona's extreme summer heat, ambient temperature plays a significant role. If your kitchen reaches 90 degrees or higher, your refrigerator will work much harder. Ensure adequate ventilation around the unit and consider if your kitchen needs better cooling.

Incorrect temperature settings can keep the compressor running. If set too cold, the refrigerator may never reach the target temperature and run indefinitely.

A faulty door switch may prevent the unit from recognizing when the door is closed. This switch typically controls the interior light and can affect the defrost timer on some models.

Low refrigerant levels, while less common in residential units, can cause continuous running. The compressor keeps working but can't achieve the necessary cooling. This requires professional service as refrigerant handling requires certification.

A malfunctioning thermostat or temperature sensor will give incorrect readings to the control board, potentially causing constant operation even when the interior is at the correct temperature.

For Sub-Zero and similar premium units, continuous running might be normal after loading large amounts of groceries or after power outages as the unit works to restore optimal temperatures.