Start with one question: does the freezer still freeze? On almost every modern refrigerator a single evaporator cools both compartments, so a cold freezer with a warm fridge points at airflow — a fan, a damper or a defrost fault — and typically lands in the $180–$400 band once a technician has fitted the part. Neither side cold points upstream at the compressor circuit or the sealed system, which is a different order of cost and, for anything involving refrigerant, licensed work.
Read this first
- An oily film near the copper lines or a weld is refrigerant, not water. Locating and repairing that circuit requires EPA Section 608 certification — it is not a DIY repair at any skill level.
- Unplug the cabinet before removing the rear freezer panel or reaching behind the kick plate. Start relays and capacitors sit right where your hand goes.
- Never thaw an iced evaporator with a heat gun or an open flame. The liner is plastic and the coil is under pressure.
What it usually means
Cooling faults sort into three families and the symptom tells you which. Warm fridge with a working freezer is an air-routing problem: the evaporator fan has stopped, the damper is stuck, or frost has closed off the evaporator. Both compartments warm with the compressor running is a heat-rejection or refrigerant problem: coils choked with dust, a dead condenser fan, or a leak. Both warm with no compressor hum at all is electrical — a start relay, an overload, or a control board.
The opposite failure is more common than people expect: a fridge that freezes lettuce is almost never broken in the cooling circuit at all. It is a damper stuck open, a thermistor reading warmer than reality, or food parked directly in the cold-air stream. Same for a wine cooler that swings five degrees between readings — thermoelectric models simply cannot hold a set point in a hot room, and that is a placement problem rather than a fault.
What to check first
Measure the real temperature, not the display
Put a glass of water in the middle of the fresh-food section for eight hours and read it with an appliance thermometer. You want 37°F, with 40°F the upper safe limit. Take a freezer reading too — it should sit near 0°F. Those two numbers determine everything that follows.
Save the food while you diagnose
A closed refrigerator holds safe temperature about four hours, a full freezer about 48. Move what matters to a cooler now rather than after the diagnosis. Food that has been above 40°F for more than two hours should be thrown out, not refrozen.
Vacuum the condenser coils
Pull the cabinet out and clean the coils at the back or under the kick plate with a brush attachment. Dust and pet hair on the coils is the single most common cause of a fridge that runs constantly and still drifts warm, and it is free to fix.
Listen for the two fans
With the doors closed you should hear the condenser fan at the bottom rear. Open the freezer and hold the door switch in — the evaporator fan behind the rear panel should run. A silent evaporator fan with a cold freezer and a warm fridge is your answer.
Look for frost on the freezer's back panel
Pull the rear freezer panel. A solid sheet of frost over the evaporator coil means the defrost circuit — heater, bimetal thermostat or adaptive control — has quit, and the ice is now blocking the airflow that cools the fridge side.
Check clearance and ambient temperature
Two inches behind and above the cabinet, and nothing stacked on top. A refrigerator or wine cooler in an unheated garage or a hot utility room is being asked to work outside what its thermostat was designed for, and will read as faulty when it is not.
DIY, technician, or licensed trade?
This is about who is allowed to do the work, not how hard it is. The bottom row is not a difficulty rating — it is the legal and safety line, and it does not move for confidence or experience.
- Cleaning condenser coils and restoring clearance around the cabinet
- Manually defrosting an iced evaporator to confirm airflow is the problem
- Testing and replacing a door gasket, and levelling the cabinet
- Moving food out of the cold-air inlet on a fridge that freezes produce
- Replacing an evaporator or condenser fan motor, a damper, or a thermistor
- Testing and replacing a defrost heater, bimetal thermostat or adaptive defrost control
- Diagnosing a main control board before you buy one — boards are rarely returnable once fitted
- Any refrigerant work: locating a leak, recovering, evacuating and recharging is EPA Section 608 certified work and venting refrigerant is illegal
- Compressor replacement, which opens the sealed circuit
Likely parts and what they cost
Our estimates for a typical US job, not quotes. “Part only” is what the component costs bought online against a model number; “installed” adds a technician’s diagnostic and labor.
| Part | Part only | Installed | Notes |
|---|---|---|---|
| Compressor start relay / overload | $15–$40 | $150–$300 | Rattles when you shake it. Cheapest real fix for a fridge that clicks and does nothing. |
| Evaporator or condenser fan motor | $40–$140 | $180–$400 | Bottom-freezer cabinets take longer to open up, so labor runs higher. |
| Defrost heater, thermostat or control | $25–$120 | $200–$450 | Fix this and the frost-blocked airflow problem goes with it. |
| Air damper or thermistor | $15–$90 | $150–$350 | The usual answer on a fridge that runs too cold rather than too warm. |
| Sealed-system leak repair and recharge | n/a — licensed labor | $400–$800 | Insist the leak is located and repaired, not just topped up. |
Prices are general estimates for typical US jobs, not quotes. What you actually pay depends on your appliance's brand and age, the part required, your region, and each shop's labour rate. Get the model number off the appliance before ordering — the same part varies in price across models.
Step-by-step guides for this symptom
7 guides cover this fault across 3 appliance types. Each one works through it in diagnostic order, with tools, parts and the point at which it stops being a DIY job.
- 45–90 minutesRefrigerator
Refrigerator Not Cooling — Narrow It Down Before You Buy Parts
Fridge warm inside? Work through the freezer reading, demo mode, condenser coils, fan motors, a frosted evaporator and the start relay before assuming compressor failure.
- 45–90 minutesFreezer
Freezer Not Freezing — Systematic Diagnosis
Freezer running but food is soft? Check coils, fans, the door seal, the start relay and the garage-ambient trap before assuming the compressor has failed.
- 30–75 minutesWine Cooler
Wine Cooler Not Cooling — Thermoelectric and Compressor Models
Wine fridge warm inside? Thermoelectric and compressor coolers fail differently. Identify which you have, then check ambient limits, fans, coils and seals.
- 30–60 minutesRefrigerator
Refrigerator Running Constantly — Causes and Fixes
A refrigerator that never shuts off wastes power and shortens compressor life. Check coils, door seals, defrost failure and fan operation with this DIY guide.
- 45–90 minutes plus a 24-hour defrostFreezer
Freezer Frost Buildup — Diagnose the Defrost System
Ice sheets on the freezer wall mean a door seal problem or a failed defrost system. Test the heater, defrost thermostat and drain with this step-by-step guide.
- 30–75 minutes plus a 48-hour logWine Cooler
Wine Cooler Temperature Swinging — Stabilise the Cabinet
A cooler that swings ten degrees will age a collection badly. Check sensor placement, thermal mass, door habits, dual zones, ambient swings and the control.
- 30–60 minutesRefrigerator
Refrigerator Freezing Food — Why It Runs Too Cold
Lettuce turning to ice and milk slushy? Diagnose an over-cold refrigerator: settings, deli drawer controls, a stuck air damper, a failed thermistor and vent blockages.