Every contemporary refrigerator in Washington DC uses a defrost heater.  But exactly what is a refrigerator defrost heater?  It is that fun little part that regulates the temperature of the fridge in order to keep the food cold.  The defrost heater is a wire filament which is enclosed in a tube sheath made of glass, quartz, aluminum or some other material.  The tube sheath gets hot when powered, thus helping the fridge through the defrost cycle.

The defrost heater is a part of the automatic defrost technology which runs for short periods of time to melt any frost that has formed.  For every six to twelve hours of compressor operation, the defrost heater is run for approximately fifteen minutes to a half-hour.  Mounted just below the evaporator coil, the defrost heater is protected from short circuits with fusible links.  On older refrigerators, the defrost timer ran continuously.  However, today’s refrigerator’s activate the defrost heater once the compressor motor runs—which is much less often—in order to save energy.  Thus, when the refrigerator door is left closed the compressor and hence the heating element will run less frequently.

It is easy to tell when a defrost heater breaks because it will normally cause the freezer to warm up a lot.  There might even be some frost which formed at the back of the freezer.

Tips for Testing a Refrigerator Defrost Heater

  • Find the Defrost Heater:  Disconnect the refrigerator’s power supply from the wall.  Open the back panel and locate the defrost heater: usually located below the evaporator coils under the freezer door or behind the back panel.  Remove any additional objects such as food or freezer shelves.
  • Check the Timer: If it is actually the timer that has broken, look for the advance screw on the timer and advance it. Wait thirty minutes.  If the timer has not advanced, replace it.  Once replaced, if the heater is still not working it’s time to move on!
  • Check the Temperature Settings: if the dial is easily accessible it might have been tapped into a new temperature. Readjust this. The defroster should start if it is working properly. Otherwise, move on!
  • Check the Air Flow: Make sure vents are not blocked and remove any dust or debris. This can cause a higher interior temperature as well.
  • Check the Condenser Coil:  Vacuum around the condenser coil to remove any dust or debris that could be causing it to operate improperly.
  • Check Wire Connections:  Untwist and unkink wires which have settled or moved out of place, and ensure they have secure connections.  Faulty connections can cause improper cooling issues.
  • Check the Thermostat:  Pull out the thermostat and see if the heater works when the thermostat is not connected.  If it works, replacing the thermostat could fix the problem.

If once all of these steps have been completed you find that the refrigerator defrost heater is still not working properly it will need to be replaced.  This is an easy fix as the old one just needs to be unscrewed and removed and the new one put in its place, but if you are not comfortable doing it contact a certified Washington DC appliance repair technician, like the ones at All Time Services!