If your freezer is holding food solid and the fridge compartment has drifted up to room temperature, there is good news buried in that symptom. The compressor is running, the refrigerant is circulating, and the sealed system is intact. Those are the failures that end a refrigerator's life.
What you have is an airflow problem, and airflow problems are cheap.
How a modern refrigerator actually cools
Almost every refrigerator sold in the last thirty years has one cooling coil, called the evaporator, and it lives in the freezer. A fan blows air across that coil, and a duct carries some of the chilled air up or across into the fridge compartment. A damper regulates how much.
That is the whole system. One cold source, two compartments, a fan and a duct.
So when the freezer is cold and the fridge is not, one of four things has gone wrong between the coil and the fridge.
The four causes
1. The evaporator coil has iced over
This is the most common by a wide margin. Refrigerators run a defrost cycle every eight to twelve hours specifically to melt the frost that builds on the coil. When the defrost system fails, frost builds until it becomes a solid block of ice, and air can no longer pass through.
The freezer stays cold because it is sitting next to a block of ice. The fridge starves.
How to check: take out the back panel inside the freezer. If you find a wall of white ice instead of a finned coil, that is your answer. The failed part is one of three: the defrost heater, the defrost thermostat, or the control board that runs the cycle.
2. The evaporator fan has failed
Without the fan, cold air does not move anywhere. The freezer still gets cold by conduction. The fridge gets nothing.
How to check: open the freezer door and listen. Most models run the fan whenever the door is closed, and pressing the door switch by hand will start it. Silence, or a grinding rattle, points at the fan. Frost can also physically block the fan blade, which brings you back to cause one.
3. The damper is stuck shut
The damper is a small flap that meters cold air into the fridge compartment. On some models it is a mechanical flap on a bimetal, on others it is a small motor driven by the control board. Either can stick closed.
4. The door seal is not sealing
Less common as a complete failure, but worth ruling out because it costs nothing. Close the fridge door on a dollar bill. If it slides out with no resistance, the gasket has hardened and warm humid air is pouring in faster than the system can remove it.
What you can try before calling
Empty the freezer, unplug the refrigerator and leave both doors open for 24 hours with towels down. This melts any ice on the coil.
Plug it back in. If the fridge cools normally for a few days and then warms up again, you have confirmed a defrost system fault. That is a genuinely useful diagnosis and it is worth telling the technician when you book.
If it never cools at all after the defrost, the fan or the damper is the likelier cause.
What not to do
Do not attack the ice with a knife, a screwdriver or a chisel. The evaporator coil is thin aluminium tubing carrying refrigerant under pressure, and puncturing it converts a cheap repair into a scrapped appliance. A hairdryer on low, at a distance, is the most aggressive tool that belongs anywhere near it.
The cost question
A defrost heater, a defrost thermostat, an evaporator fan or a damper are all inexpensive parts, and all four are same-visit repairs. This is why the fridge-warm-freezer-cold combination is one we are always happy to see: it almost never ends with us telling someone their refrigerator is finished.
Compare that with a fridge where nothing is cold in either compartment. That can still be a cheap fix, a start relay for instance, but it can also be a failed compressor, and that is the conversation nobody wants.
See what a refrigerator repair visit covers.
FAQ
How long can food stay safe while I wait?
Food in the fridge is safe for about four hours above 40°F. The freezer will hold for a day or more as long as the door stays shut. Move anything critical from the fridge into the working freezer.
Does this happen more on some brands?
Ice makers freezing over and evaporator fans icing up are common enough on French-door models across every brand that we carry the parts as stock. Samsung and LG French-door units come up often, mostly because there are so many of them in service.
My fridge is running constantly. Is that related?
Yes. When the fridge compartment cannot reach its setpoint, the system never satisfies and the compressor never cycles off. Fixing the airflow fixes the running time.
Should I just buy a new refrigerator?
Not on this symptom. This is the cheap end of refrigerator faults. Ask about replacement when a technician tells you the compressor or the sealed system has gone.
We cover refrigerator faults across every town in our service area, and refrigeration calls get scheduling priority over everything else.
