Fridge Not Cooling But The Light Is On

What's happening?

A working light proves the appliance has power, so the fault is inside the cooling system rather than at the socket. On a fridge freezer, the most common cause is not the compressor at all: the evaporator behind the back panel of the freezer ices up, the fan that pushes cold air into the fridge compartment either fails or gets blocked by that ice, and the fridge warms while the freezer stays cold. Next most likely is a defrost fault, which is what allowed the ice to build up in the first place. Then there are the thermostat and the control board. A failed compressor or a refrigerant leak is the least common and the most serious, because sealed system work is regulated and often uneconomic. That is why the pattern of which compartment is warm matters so much.

What usually causes it?

• A frosted-over evaporator behind the freezer back panel, blocking airflow to the fridge
• A failed evaporator fan: no airflow into the fridge when the door switch is held closed
• A defrost fault, meaning the heater, defrost thermostat or timer is not clearing frost
• Condenser coils or the compressor compartment choked with dust at the back or underneath
• A faulty thermostat or temperature sensor, so the compressor never runs long enough
• Door seals not sealing, letting warm moist air in and driving continuous frosting
• Overpacking, or vents inside the cabinet blocked by food pushed against the back wall
• A refrigerant leak or failed compressor: the sealed system fault, and the least common

Is it dangerous?

The food is the immediate issue: chilled food held above 8°C is a food safety problem, and a fridge that has been warm for hours needs its contents assessed rather than assumed. Electrically, a fridge that trips the RCD or smells hot should be unplugged. The bigger point is about repairs: the sealed system holds refrigerant, and modern domestic fridges commonly use isobutane, which is flammable. Never puncture the pipework, and understand that F gas work is qualification-controlled: GOV.UK states it is against the law to work with F gas without the correct qualifications.

Can I fix it myself?

The useful checks are all external. Note which compartment is warm and whether the freezer is still cold, since that single fact points at airflow rather than the compressor. Pull the appliance out and vacuum the condenser coils and the compressor area: dust here is a real and common cause. Check the door seals by closing the door on a sheet of paper and seeing whether it drags when pulled. Make sure the cabinet is not overpacked and the internal vents are clear, and check the temperature dial has not been knocked. Take everything out and leave the doors open for a full defrost, then see whether it cools again: if it does, you have a defrost fault, not a dead compressor.

When should you call an appliance repair engineer?

Call an appliance engineer when a full defrost restores cooling only temporarily, when the fridge is warm but the freezer is fine, when you can hear no fan with the door switch held in, or when the compressor is running constantly without cooling. Call urgently if the appliance trips the electrics or smells hot. Sealed system work needs the right qualifications, so ask about that specifically rather than accepting a general offer to regas a domestic fridge.

What will the appliance repair engineer actually do?

• Establish which compartments are warm and take actual temperatures rather than working from the dial
• Remove the freezer back panel to inspect the evaporator for frosting and test the fan and door switch
• Test the defrost circuit: heater, defrost thermostat and timer or board control
• Check the condenser, compressor and thermostat, and measure running current at the compressor
• Test the door seals and check for a cabinet or hinge problem driving continuous frosting
• Repair the fan, defrost or thermostat fault, or advise replacement where the sealed system has failed

Which compartment is warm tells you the cost

Before anyone quotes, work out the pattern. It separates the repairs that are worth doing from the ones that usually end an appliance, and it stops a fan fault being sold as a dead compressor.

• Fridge warm, freezer cold. Airflow: iced evaporator, failed fan or a defrost fault. Repairable.
• Both warm, compressor silent: thermostat, sensor, board or a start relay. Usually repairable.
• Both warm, compressor running constantly: refrigerant loss or a blocked system. Often uneconomic.
• Cools after a full manual defrost, then fails again: a defrost circuit fault. Repairable.
• Trips the RCD or smells hot: unplug it and treat it as electrical before anything else.

Who fixes this

• Fridge and freezer repair

Questions people ask

Sources & References

1. GOV.UK: Qualifications to work with F gas
2. GOV.UK, Fluorinated gas (F gas): guidance for users, producers and traders
3. GOV.UK: Consumer rights
4. Beko: Product support