How Frost-Free Defrost Works
Frost-free models run a timed defrost cycle several times per day, using a heater to melt ice from the evaporator coil. When this system fails, ice builds up gradually until it blocks airflow and the machine stops cooling properly.
Common Defrost System Faults
Defrost Heater Failed
The heater element that melts the ice has burned out. Replacement cost: £80–£150.
Defrost Thermostat (Bimetal)
This safety switch cuts power to the heater when the coil is clear. If it fails in the open position, the heater never fires. Replacement: £60–£110.
Defrost Timer or Control Board
On older models a mechanical timer controls defrost cycles; on modern models the PCB does this. Timer: £70–£120. PCB: £150–£280.
Temporary Fix
Unplug the freezer for 24–48 hours to let the ice melt manually, then plug back in. This buys time but the fault will recur unless repaired.
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