Chest freezer not working but the light is on? What to check

A chest freezer with a light that comes on but food that is slowly thawing is a common call for us. The light and the cooling system are separate. The light proves the freezer has power, nothing more. The part that makes the cold is the compressor, a sealed system of pipes, a thermostat and, on some models, a fan.

Because chest freezers are often kept in garages, outbuildings and back rooms, they get dusty, hot and ignored. Here is what usually goes wrong and what to do.

1. The thermostat is set wrong or has failed

Check the dial first. A knob nudged to the lowest setting, or one that has worn out, stops the compressor from running. Turn it to the coldest setting and listen. If the compressor still does not start, the thermostat or the starting parts may have failed.

2. The compressor is not starting

Stand next to the freezer and listen. A healthy compressor hums, then settles. A click every few minutes followed by silence usually means the start relay or overload protector is worn. These are small, inexpensive parts, and the fix is often quick. If the compressor itself has failed, a technician needs to confirm it.

3. The condenser is clogged with dust

A chest freezer sheds heat through a coil in its walls or at the back. In a hot garage, with dust and cobwebs on the coil or the freezer hard against a wall, it cannot shed heat and stops cooling properly. Pull it a few centimetres from the wall and clean any exposed coil.

4. The lid seal is leaking

A perished or dirty lid seal lets warm, humid air in. You see frost building up around the rim and the freezer runs constantly without catching up. Close the lid on a sheet of paper. If it slides out easily, the seal needs attention.

5. There is a gas leak or a blockage

If the compressor runs but the freezer never gets cold, the sealed system may be losing gas or may be blocked. A regas without finding the leak does not repair the problem permanently, because the gas escapes again. This is a job for a technician, not a store-bought kit.

What you can safely check

• Make sure the freezer is plugged in and the socket works. Test it with a lamp.
• Check the thermostat dial setting.
• Listen for the compressor starting and for any clicking.
• Feel the back or sides. Warm is normal. Hot is not.
• Clean the dust off any exposed coil with the freezer switched off at the wall.
• Check that the lid closes properly and the seal is clean.

What to do with the food

If the freezer has stopped, keep the lid closed. A full chest freezer holds its cold for a day or two. Food that still has ice crystals can generally be refrozen. Meat, fish, dairy and cooked meals that have been warm for more than about two hours should be thrown away.

What a repair costs

We diagnose the fault first. Call-out fees start from R250 and depend on your area. Minor repairs, such as a thermostat or a start relay, typically cost between R350 and R950. Major repairs start from R1,250. We will tell you honestly if the freezer is not worth repairing.

Call us with the make, the age and what you can hear, and we will tell you the likely cause before we come out. We repair chest and upright freezers across Durban.