What each part does, what points to it, and whether it is something you can check or a job for a technician.
Evaporator fan stopped or iced
The fan behind the freezer's back panel pushes cold air into the fridge section. When its motor fails or ice jams the blades, the freezer stays cold and the fridge warms.
It is the most common culprit when the freezer holds and the fridge does not. Open the freezer and listen: a steady hum is normal, while silence, clicking, chirping or grinding points here. Replacing it means removing interior panels, so it is technician work.
Fridge warm but freezer cold: what it means
Air damper stuck closed
A small motorized flap between the freezer and the fridge controls how much cold air crosses over. When it sticks closed, the fridge slowly warms while the freezer stays cold.
Dampers fail electrically or freeze shut. On many models you can hear a healthy damper open and close when the fridge has been left alone. A silent damper housing crusted with frost is the giveaway.
How the damper fails, and what else to check
Defrost system failure
A heater melts the frost off the cooling coil several times a day. When the heater, its thermostat or the control fails, frost slowly buries the coil until air cannot pass.
Look for a thick sheet of frost on the freezer's back wall and cooling that fades over one to two weeks. A manual defrost brings the cooling back for a while, then it fades again, because the failed part is still there.
Why is your freezer frosting up? Causes and fixes
Vents blocked by food
Food pressed against the back wall, or a fridge packed so full that air cannot move, leaves warm spots even when every part works.
A freezer packed solid against its vents, or nearly empty in a hot kitchen, also struggles. About three-quarters full is the sweet spot. Leave space around the vents and give the fridge a few hours to recover.
Refrigerator not cooling? 8 causes and how to fix them
Door not sealing
A dirty, worn or folded door gasket lets warm, humid air in all day. The fridge runs longer, frost builds near the door and the freezer goes soft at the edges.
Dirt is a more common cause than damage. A door that sags, a cabinet that tilts forward, or a drawer that stops the door from closing leaves the same gap. In humid weather a bad seal can also drip water inside that looks like a leak.
Refrigerator door not sealing? Gasket problems and fixes
Dirty condenser coils or a stalled condenser fan
The coils under or behind the fridge release the heat taken out of the cabinet, and a small fan near the compressor pulls air across them. Dust, pet hair or a stalled fan make the fridge run longer and cool less.
The freezer needs the deepest cold, so it often shows the shortage first. Cleaning the coils is one of the most common fixes our technicians see, and in homes with pets it is worth doing twice a year. On a Sub-Zero, a Vacuum Condenser message is the reminder to do it.
Refrigerator not cooling? 8 causes and how to fix them
Temperature sensor or control board
A sensor called a thermistor tells the control board how cold the cabinet is. When it drifts, the fridge may run all the time and freeze food in the fresh-food section, or barely run at all.
A control that keeps losing its settings, or stops cooling with no code, has its own fault. Both need a meter to test against the maker's specification, so this is a diagnosis job, not a guess.
Refrigerator running constantly? Why it never shuts off
Compressor not starting
A click, a few seconds of hum, then another click, repeating every few minutes, usually means the start relay is trying to start the compressor and failing.
Either the relay has failed, which is a modest repair, or the compressor itself cannot start. A technician can tell them apart in minutes with a meter. A fridge with the light on but no compressor hum at all can point to the same parts or to the control board.
Refrigerator compressor hot or clicking: is it failing?
Sealed system: compressor or refrigerant
The compressor, coils and refrigerant lines form a sealed circuit. A compressor losing capacity, a refrigerant leak or a restriction shows up as weak cooling on both sides while the fridge runs constantly.
Other signs are a frost patch on only part of the cooling coil and cooling lost slowly over weeks. Fans and defrost faults can look the same, so they are ruled out first. Only certified technicians may open the refrigerant circuit, and it is the most expensive kind of fridge repair, so age matters most here.
Sealed system repair explained: why some fridge fixes cost more
Demo or showroom mode
Store display mode keeps the lights and display on but switches the cooling off. It can turn on by accident after a power blip or a long button press.
Samsung shows OF OF and Sub-Zero shows Showroom. On other brands, a lit display with no cooling is the classic sign. The button combination to exit is in your manual or on the maker's support site. If cooling comes back, nothing was broken.
Samsung refrigerator not cooling: brand-specific fixes
Clogged or frozen defrost drain
Defrost water runs down a small drain to a pan under the fridge. When food debris or ice blocks it, water backs up under the crisper drawers or freezes into a sheet of ice on the compartment floor.
It is the single most common refrigerator leak, and flushing the drain usually clears it. If it keeps refreezing, a technician can fix the drain heater or fit an improved drain part.
Why is my refrigerator leaking water? Causes and fixes
Water line, fitting or inlet valve
On a fridge with an ice maker or dispenser, a thin water line runs to a valve at the back. A loose fitting, a cracked plastic line or a failing inlet valve leaves drips or a slow puddle behind the fridge.
Shut the supply valve until it is fixed. Old plastic lines are worth replacing with braided ones, because a burst line can release a lot of water while nobody is home. The same valve feeds the ice maker, so a failed valve can also stop the ice.
Where the water shows up, and which part it points to
Cracked or loose drain pan
Defrost water is meant to evaporate from a pan near the compressor. A cracked or displaced pan lets it reach the floor, usually as a small puddle centered under the fridge.
Checking the pan means removing the lower panel with the fridge unplugged. A new pan is an inexpensive part. A loose pan can also rattle or buzz.
Why is my refrigerator leaking water? Causes and fixes
Water filter not seated or clogged
A leak that starts right after a filter change usually means the filter is not fully seated, or it is a poorly fitting off-brand part. A clogged filter slows water to the ice maker.
Small or hollow cubes in the weeks before the ice stopped are the classic sign of a clogged filter. Air in the line after a filter change can also make the dispenser drip for a while.
Ice maker not making ice: a troubleshooting guide
Ice maker off, too warm or not filling
Most ice makers stop for simple reasons: the shutoff arm or switch is off, the freezer is warmer than about 5°F, the filter is clogged or the fill tube has frozen.
Look at the mold. Bone dry means water never arrives. A slab of ice across it means the valve is dribbling. Cubes that form but never drop point at the ice maker's own motor or control. A buzz about every 15 minutes with no ice means it is trying to fill with no water.
Ice maker not making ice: a troubleshooting guide
Something loose or touching
A rattle or buzz from the back is often a loose drain pan or tubing touching the cabinet, not a failing part.
Make sure nothing on top of the fridge is vibrating and the cabinet is not touching the wall or the cabinets. A buzz while the ice maker fills is normal, and so are gurgling, popping and sizzling during defrost.
Guide for common appliance sounds