The defrost system in your fridge freezer prevents ice buildup on the evaporator coils. When it fails, ice can accumulate, reducing airflow, causing temperature fluctuations, and eventually damaging other components.
Symptoms of defrost system failure
- Excessive frost or ice on freezer walls
- Water pooling inside the fridge
- Fridge running constantly without maintaining temperature
- Loud noises from fans struggling against ice
Common causes
Defrost heater failure
The heater melts frost during the defrost cycle. If it stops working, ice accumulates and airflow is blocked.
Defrost thermostat or sensor issues
These components detect temperature and control the heater. If faulty, the heater may not activate at all.
Defrost timer or control board faults
The timer or board schedules defrost cycles. When they fail, the system cannot regulate ice build-up effectively.
Repair options and costs
- Defrost heater replacement: £100–£200
- Defrost thermostat replacement: £60–£150
- Control board or timer replacement: £150–£300
Related problems
- Fridge freezer ice build up problems explained
- Fridge freezer leaking water inside or outside
- Blocked fridge drain hole problems
Get a repair quote
Professional engineers can test each defrost component to restore proper operation and prevent recurring ice buildup.
Visit our homepage to get free local repair quotes.