Before testing the defrost heater, unplug
the refrigerator to avoid an electrical shock hazard.
The defrost heater is usually located at
the back of a side by side freezer or under the floor of a
top freezer. It will be necessary to remove obstructions such
as the contents of the freezer, freezer shelves, icemaker
and the inside rear or bottom panel of the freezer.
The panel may be held in place by retainer
clips or screws. Remove the screws or depress the retainer
clips with a small screwdriver. On some older top freezers
it is necessary to remove the plastic molding to access the
freezer floor. Removal of that molding can be tricky -never
force it. If you decide to remove it, you do so at your own
risk - it is prone to breaking. Warm it first with a warm,
wet bath towel.
There are three primary types of defrost
heater elements; exposed metal rod, metal rod covered with
aluminum tape or a wire coil inside a glass tube. All three
elements are tested in the same way.