A fridge freezer where the freezer still works but the fridge has gone warm is one of the most misdiagnosed faults in the trade. The good news: because one half still freezes, the compressor and gas circuit are usually healthy. The fault is almost always in the defrost system or the air path between the two compartments.
How a frost-free fridge freezer actually works
In a modern frost-free appliance there is one evaporator, usually behind a panel in the freezer. A fan pushes cold air up into the fridge compartment through a duct. Every few hours the appliance runs a defrost cycle: a heater melts the frost off the evaporator, and the melt water drains away.
When that cycle stops working, the evaporator ices over solid. Air can no longer pass, and the fridge — which sits at the end of the air path — warms up first while the freezer stays cold.
The three usual culprits
- Defrost heater — the element that melts the frost has failed.
- Defrost sensor or thermostat — the appliance never knows the evaporator is iced, so it never starts a defrost.
- Defrost timer or control board — the scheduling side has failed.
Less commonly, the evaporator fan motor has seized, or the drain tube has blocked so melt water refreezes inside the compartment.
Why switching it off for a day only helps for a week
Defrosting manually clears the ice and the fridge comes back to temperature. But if the heater or sensor is faulty, the ice simply builds up again — which is why we see the same appliance three or four times when an owner has tried the DIY route first.
The right approach is to test the heater for continuity, check the sensor readings at known temperatures, and confirm the board is commanding a defrost. That takes about twenty minutes with the right meter and the right knowledge of the model.
What it costs and how long it takes
Labour is £90 for refrigeration — fridges, freezers and fridge freezers — because diagnosing a sealed system takes longer than a simple element change. The part is quoted before fitting. Most defrost repairs are completed on the first visit because our vans carry the common heaters, sensors and fans for the major brands, including Samsung twin-cooling models.
If the compressor or the sealed circuit itself has failed, we will tell you before you spend anything further — at that point a replacement is usually the sensible decision.