How Freezers Work

The Frosty Menace: Freezer Frost

The worst thing that can happen to a freezer is frost, which isa thick, cold dusting of fine ice that covers everything inside the freezer turning it all into one big solid icy mess. What can cause frost?

  • Opening it too often and allowing too much warm room temperature air in, which can shut down the freezer elements that are built to process only cold air
  • Blocking air flow by pushing the freezer too close to a wall, which makes the condenser coils act less efficiently
  • Having a loose rubber seal around the door, which allows that pesky room temperature air in

Basically, in each of these situations, warm air mixes with sub-freezing air. The result is frost. Many newer-model freezers have an automatic frost prevention feature, which regulates temperatures to keep the inside temperature consistently where it needs to be. If you don't have that feature, here are some other ways to prevent frost:


  • Set your freezer's thermostat to 0 degrees Fahrenheit -- not too much colder or warmer [source: NCHFP].
  • Open it only when you need to, so as to not wear down the rubber seal around the door.
  • If your freezer has coils on the back, make sure you have at least 3 inches between the coils and the wall.

If you aren't able to get rid of frost as fast as it accumulates -- say your rubber seal is shot, an expensive internal part is overworked, or a coil is fried -- it might be time to get a replacement. Up next, we'll look at what you need to consider when it's time to purchase a new freezer.