When the freezer is cold but the fridge is not, the fridge is not making its own cold. On nearly every household fridge freezer the cold is produced by one evaporator in the freezer section and pushed into the fridge by a fan, through a vent, past a flap called the damper. So the fault sits on that delivery path: frost has built up over the evaporator and sealed the vents, the damper is stuck shut, the fan has stopped, or food is packed against the vent and the air cannot get through. The safe checks are to look for frost on the rear panel of the freezer, listen for the fan, make sure the vent and damper between the compartments are clear, then run a full defrost. If the fridge cools after a defrost but warms up again within days, the defrost system has failed, and that is a technician’s job.
This is a narrower problem than a fridge that is warm everywhere. The compressor is running and the freezer is holding, so the sealed system is rarely the issue. Our general guide to a fridge not getting cold covers whole-fridge faults; this one deals only with the air not getting from the freezer to the fridge.
Fridge not cold but freezer is: how the cold air is meant to move
Behind the rear panel of the freezer sits the evaporator, a coil that gets very cold when the compressor runs. A small fan draws air across it and pushes that air two ways: around the freezer, and down a duct into the top of the fridge compartment. The damper is the door on that duct. It opens when the fridge thermostat or thermistor asks for cold and closes when the fridge is at temperature, so the fridge section is borrowing cold from the freezer on demand. A few times a day a heater melts the frost off the coil.
If any link in that chain fails, the freezer stays cold while the fridge creeps up over a day or two. Rock-hard ice cream beside milk that is on the turn is the classic sign.
An iced-up evaporator blocking the vents
The most common cause is frost. When the defrost heater, the defrost thermostat, the timer or the control board fails, frost keeps building on the coil until it becomes a solid sheet of ice over the rear panel of the freezer and blocks the vents. You will usually see it: a furred, frosty back wall and ice around the vent slots. A freezer door left ajar, or a worn freezer seal letting humid air in over a Perth summer, produces the same picture, so check the seal and the door while you are looking. Our guide to a freezer icing up covers the seal side in more depth.
The test is a full manual defrost. Move the food into an esky, switch the fridge off at the wall, open both doors and put towels down. Give it a full day, not a couple of hours, so the ice behind the panel goes as well as the ice you can see. Switch it back on, wait overnight and check the fridge with a thermometer. If it is cold again, you have confirmed the cause; note the date. Frost and a warm fridge back within a week or two means the defrost system is faulty and needs a technician.
A damper that is stuck shut
The damper sits at the top of the fridge compartment where the duct from the freezer arrives. On simpler fridges it is a manual slider or dial, and it gets knocked closed when the shelf is loaded, so set it to the middle and confirm it moves through its full travel. On most modern models the damper is a motorised flap. Ice can jam it, the small motor can fail, or the thermistor that tells it to open can drift, and in each case the flap stays shut and the fridge goes without cold air.
Empty the top shelf and hold your hand at the vent while the fan is running. With the damper open you feel a steady cold breeze. Nothing at all, with the fan audible in the freezer, points to the damper. Replacing a motorised damper means working on the control wiring, so that part is ours.
The evaporator fan has stopped
No fan, no delivery. Open the freezer door, find the door switch on the frame and press it in so the fridge thinks the door is closed. Within a few seconds you should hear the fan spin up behind the rear panel. Silence while the compressor hums at the back means the fan motor or its wiring has failed. A ticking or scraping noise means the blades are hitting ice or the bearing is worn. Wait ten minutes and try again before concluding anything, because most fridges hold the fan off during a defrost.
Fan faults are not a home repair. The motor sits on the evaporator behind the panel, alongside the defrost heater and the wiring, so book a technician.
Overloading and blocked vents
The cause we most like to find is the easiest one. A freezer packed solid to the back wall, bags of frozen bread pressed against the vent slots, or a large roast pushed up against the vent at the top of the fridge will starve the fridge of cold air even when every component is working. Leave a gap between the food and the back wall of the freezer, and keep the vent area at the top of the fridge clear, since that is where the cold arrives.
Check the settings as well. A control knocked to a warmer position leaves a fridge not cold enough for milk. The honest test is a fridge thermometer on the middle shelf overnight; our guide to what temperature a fridge should be covers the target range.
When a fridge not cooling needs a technician
Clearing the vents, checking the settings, cleaning the seals and running a full defrost are safe and often enough. Everything else on the delivery path is behind a panel and wired in: the defrost heater, thermostat, timer or control board, the evaporator fan motor, a motorised damper and its thermistor. If the freezer has also started to slip, or the compressor runs constantly and hot, you are into whole-fridge faults instead, and the same call applies. Meanwhile, keep the doors closed and move meat and dairy into an esky with ice bricks.
That is where our team comes in. CAI Appliance Services repairs fridges across Perth, with fully qualified mobile technicians who come to you. We are an authorised service agent for Bosch and Electrolux, and we repair all major brands including LG, Samsung, Miele, Fisher and Paykel, Smeg and Whirlpool, so the work is done with the correct parts. Call CAI on 0415 343 413 to book a technician.
Fridge Not Cold but Freezer Is?: the quick version
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Frequently asked questions
Why is my fridge not cold but the freezer is working?
Will defrosting fix a fridge that is not cooling?
How do I know if the evaporator fan is broken?
Is it worth repairing when the freezer still works?
Need more on fridge faults? Read our guides on a fridge not getting cold, a freezer icing up and what temperature a fridge should be, or book a Perth technician with CAI.
