The Coil in the Back of My Freezer Is Hot

Refrigeration

• When you hear the refrigerator pump running, the condenser coil in the appliance’s back heats up. After the thermostat registers the correct temperature and the system shuts off, the condenser coil cools. The refrigeration system depends on a sealed circuit of tubes and coils containing a liquid that boils at below-freezing temperatures. If the coolant leaks out, the freezer runs constantly without dropping the freezing compartment’s temperature. The frozen food gradually warms and the condenser coil stays cool. The refrigeration system depends on an energy transfer when coolant transitions between gas and liquid states.

Compression

• The freezer's compressor makes the loudest noise you hear. This pump injects a controlled stream of liquid coolant into the evaporator coils hidden within the insulated freezer compartment. Even though the compartment’s temperature falls below freezing, the contents still provide enough heat to boil the refrigerator's coolant. As the liquid absorbs heat and vaporizes, it flows to coils outside the insulated freezer, taking heat energy with it. If ice forms on the evaporator coils or the freezer compartment walls, the energy transfer slows and the refrigerator works harder. Automatic defrosting cycles remove ice buildup and keep the freezer running efficiently.

Evaporation

• Outside the freezer section, the gas condenses on the condenser coil’s inside walls. As the hot gas turns to liquid again, the heat energy transfers to the condenser coil metal. In this part of the system, efficient operation depends on how well the appliance conveys that heat to the room air. The fan that runs during this cycle blows room air over the condenser coil carrying the away. Freezers work best at moderate room temperatures. Dirt or grease building up on the condenser coil from humid, smoky air in the kitchen insulates the metal, slowing the heat transfer.

Maintenance

• Some freezers include air filters inside the freezer compartment that need regular cleaning or replacement. Clogged filters interfere with the defrost cycle. Consult the manual and check for dirty filters if ice builds up. Kick screens located at the bottom of a refrigerator freezer can clog with lint restricting air flowing to the condenser coil. Regular cleaning keeps air flowing properly. Some models need extra space in back at either side and above the cabinet ensuring air flows correctly to critical parts of the system. Ambient temperature also matters. Above 110 degrees Fahrenheit or below 55 F, a Frigidaire freezer can't maintain correct freezer temperatures.