Why Is My Frost-Free Refrigerator Accumulating Frost in the Freezer Compartment?

Frost-free refrigerators and freezers use a fan and drain unit to keep frost from condensing on the walls of the freezer compartment.

Causes

Excessive frost buildup can keep a freezer from functioning.Excessive frost buildup can keep a freezer from functioning.
These convenient appliances cost more than basic freezers but don't need defrosting several times per year. Sometimes, however, frost-free freezers may develop frost and ice buildup.

Frost building up inside the freezer usually indicates a problem with the refrigerator's self-defroster. This system gently heats the freezer compartment to melt the frost and drains any water into a pan under the freezer. If this system isn't working, frost builds up in the freezer compartment and on the evaporator coils.

Potential Problems

A freezer with built-up frost isn't just annoying; the frost is also likely to stop the freezer from functioning correctly. When frost builds up on the evaporator coils, they don't get the air flow they need to work correctly. Eventually, the freezer stops cooling entirely and food can spoil. A manual defrost will work temporarily but won't correct the root problem.

Solution

Manually defrost the freezer by removing all food and turning the unit off for one to two days. If the freezer works properly after this, look at the defrost heater -- a component hidden behind the freezer's interior panel. If it looks damaged, it may need to be replaced. Problems in the defrost thermostat and timer can also cause excessive frost but are hard for homeowners to identify. If you suspect these problems, call a repair technician.

About the Author

G.D. Palmer is a freelance writer and illustrator living in Milwaukee, Wis. She has been producing print and Web content for various organizations since 1998 and has been freelancing full-time since 2007. Palmer holds a Bachelor of Arts degree in writing and studio art from Beloit College in Beloit, Wis.