How does a defrosting heater work on a refrigerator?
This heater is used to defrost the appliance automatically. During the defrosting cycle the ice on the back wall melts and runs down the back wall into a channel. It is then directed through a hole out through to the back and runs into the evaporator tray.
What should I do if the defrost button in my Refrigerator?
Some refrigerators have an Adaptive Defrost Control. This is what makes a refrigerator energy efficient. It varys the length of time it takes the machine to go into defrost. So instead of the energy hogging heater coming on every eight hours, it may be 24 hours, 18 hours, 10.5 hours, who knows.
How long does a defrost cycle on a refrigerator last?
On Adaptive Defrost Controls, when the heater shuts off, shortly after the machine exits defrost mode. Basically if the heater only stays on for ten minutes, the whole defrost cycle will only be about 12 or 13 minutes long. Basically when the heater comes on, it starts to melt the frost on the evaporator.
Why does my freezer get too warm at the end of defrost cycle?
This could be due to a malfunction of the defrost termination thermostat. This is the component in charge of turning off the defrost heater at the end of the defrost cycle, when the evaporator gets up to 38 to 47 degrees F. It can normally be found on the evaporator tubing.
What to do if your defrost heater is not working?
If the defrost heater assembly doesn’t work, the entire defrost system will be inoperative, and the evaporator coils will continue to have frost accumulate. Use a multimeter to determine if the defrost heater is working properly.
Why does my defrost thermostat not turn on?
The defrost bi-metal thermostat shuts off the refrigerator defrost heater if the heater gets hot enough to damage the evaporator. If the defrost bi-metal thermostat trips to shut off the defrost heater but doesn’t reset, the defrost heater won’t turn on.
What to do if your refrigerator is not defrosting?
If the defrost heater does not operate continuously, replace it. The defrost cycle is managed by the defrost control board. The board determines how frequently the defrost cycle needs to run. If the board is defective, the defrost cycle will never be initiated.
What kind of heater do you use to defrost coils?
The energized heater supplies enough heat to completely defrost the coils. The resistive heaters used on a typical electric defrost system are sized to provide sufficient heat to effectively defrost the coil’s surface. Their capacity is normally rated in watts per foot.
