Freezer Not Freezing?
A freezer that has stopped freezing is most commonly caused by a faulty door seal letting warm air in, incorrect temperature settings, a failed defrost system causing frost build-up to block airflow, a broken evaporator fan, or in more serious cases a failing compressor or refrigerant leak. Most of the simpler causes can be identified and sometimes resolved at home. If you have food at risk, see our guide to what to do if your freezer stops working first.
How cold should a freezer be?
A correctly functioning domestic freezer should maintain a temperature of -18°C or below. This is the temperature at which food is safely preserved and ice cream remains firm. If your freezer is running warmer than this, food will begin to deteriorate and some items may start to thaw even if the freezer appears to be running normally.
The easiest way to check your freezer’s actual temperature is with a standalone freezer thermometer, which costs a few pounds from most supermarkets and kitchen stores. Do not rely solely on the appliance’s own temperature display, as a faulty sensor can cause the display to show an incorrect reading even when the compartment is not reaching the set temperature.
What are the most common reasons a freezer stops freezing?
Temperature set incorrectly
Before assuming a mechanical fault, always check the temperature setting. Many freezers are accidentally adjusted when cleaning or when children reach the controls. The target setting is -18°C. If your appliance uses a numbered dial rather than a digital display, a setting of between 3 and 5 on a 1 to 7 scale is typically appropriate for -18°C, but consult your model’s manual for the correct value.
Faulty or damaged door seal
The door or drawer seal on a freezer creates an airtight barrier that keeps cold air in and warm air out. If the seal is torn, perished, warped, or simply not closing correctly, warm air constantly enters the compartment and the freezer must work continuously to compensate, often without being able to reach or maintain the target temperature. A faulty door seal is one of the most common and most overlooked causes of a freezer running warm.
Defrost system failure causing frost build-up
In frost-free freezers, a built-in defrost system automatically melts any ice that forms on the evaporator coils during normal operation. If the defrost heater, defrost thermostat, or defrost timer fails, ice accumulates progressively on the evaporator coils until the frost build-up is thick enough to block airflow entirely. When airflow through the evaporator is blocked, the freezer loses the ability to circulate cold air effectively and temperatures rise even though the compressor may still be running.
Evaporator fan failure
The evaporator fan circulates cold air from the evaporator coils throughout the freezer compartment. If the fan motor fails or the fan blade becomes obstructed, cold air stops circulating and temperatures rise quickly despite the compressor operating normally. You may hear the compressor running but notice the freezer is not cold – this combination of symptoms is a common indicator of an evaporator fan problem.
Poor location or ventilation
Freezers require adequate ventilation around the condenser coils, typically at the back or underneath the appliance, to release the heat extracted from the freezer compartment. If the appliance is positioned too close to a wall, is installed in an alcove without clearance, or is placed in an environment that is too warm, the condenser cannot release heat efficiently and the freezer struggles to maintain the target temperature.
Compressor or start relay failure
The compressor is the heart of the refrigeration system, pumping refrigerant through the coils. If the compressor has failed or the start relay that initiates the compressor is faulty, the appliance cannot cool at all. A failed start relay is a relatively inexpensive component that can sometimes be replaced without a full compressor replacement. Compressor failure itself is a more significant repair. If the freezer is completely silent with no compressor noise, this warrants investigation by an engineer.
Refrigerant leak
Refrigerant is the gas that circulates through the sealed refrigeration system and transfers heat out of the freezer. A refrigerant leak causes the system to gradually lose its ability to cool as the refrigerant level drops. Signs of a refrigerant leak include the freezer running constantly without reaching temperature, oil staining around joints in the pipework, and in some cases a faint chemical smell. Refrigerant handling requires specialist equipment and Gas Safe registration; this is not a DIY repair.
Temperature sensor or thermistor fault
The temperature sensor monitors the internal temperature of the freezer and tells the control board when to run the compressor. If the sensor develops a fault, it can send incorrect readings to the control board, causing the compressor to cycle off too early or not run at all. A faulty sensor can also cause the appliance’s own temperature display to show an inaccurate reading, making the fault harder to identify without a separate thermometer.
Specific causes for fridge freezers where only the freezer is affected
If you have a fridge freezer and the fridge section is cold but the freezer compartment is not freezing, this narrows the likely cause considerably. The compressor is almost certainly working, as the fridge is cooling, which rules out compressor failure and refrigerant leak as primary suspects.
Many fridge freezers share a single evaporator between the fridge and freezer compartments, with a damper or air diffuser controlling how cold air is distributed between the two sections. If the damper motor fails in the open position, the fridge may receive too much cold air while the freezer gets too little. If it fails closed, the reverse occurs. A fridge that is too cold while the freezer is too warm is a classic symptom of this fault.
In a combined fridge freezer with a single shared evaporator, frost build-up on the evaporator affects both compartments but tends to be noticed first in the freezer, where the temperature targets are more demanding. If the fridge is running slightly warm too, a defrost system fault affecting the shared evaporator is the likely cause.
On a fridge freezer, the freezer compartment typically has its own separate door or drawer with its own seal. A failing freezer seal will allow warm air into the freezer section only, leaving the fridge unaffected. This is worth checking carefully, particularly around the corners of the seal where wear and distortion are most common.
Some larger fridge freezers have separate evaporator fans for the fridge and freezer sections. If the freezer fan fails while the fridge fan continues to operate, the fridge will remain cold while the freezer warms up. Listening carefully at the freezer vents for fan noise when the appliance is running can help identify this fault.
How to diagnose a freezer not freezing: step by step
Step 1: Check the temperature settings
Before anything else, check the temperature setting on the appliance. If you have a digital display, confirm the freezer is set to -18°C or lower. If you have a dial, ensure it has not been accidentally turned towards the warmest setting. If someone else in the household uses the appliance, confirm the setting has not been changed recently.
Step 2: Check the door or drawer seal
Close the freezer door on a piece of paper or a thin card. If you can pull the paper out without significant resistance, the seal is not creating an effective air-tight closure at that point. Work around the full perimeter of the door checking the seal in this way, paying particular attention to the corners. Also inspect the seal visually for any tears, splits, flattening, or sections where the seal has pulled away from the door.
A perished or damaged door seal can often be replaced as a straightforward repair. Replacement seals for most major brands are available through our appliance spare parts section.
Step 3: Check the location and ventilation
Ensure there is adequate clearance around the appliance as specified in the user manual, typically a minimum of 50mm at the sides and 100mm at the rear. Check that the condenser coils at the back of a freestanding appliance are not dusty or covered. Dusty condenser coils reduce heat transfer efficiency significantly and can prevent the freezer from reaching target temperature. Vacuum the coils gently if they are accessible and visibly dusty.
Also check the ambient temperature of the room. Most freezers are rated for operation between 10°C and 43°C. A garage freezer in winter that drops below the minimum operating temperature, or a freezer in a hot kitchen or utility room that regularly exceeds the maximum, will struggle to maintain performance within its specified range.
Step 4: Defrost the freezer manually
If you suspect frost build-up on the evaporator is blocking airflow, a manual defrost can confirm and temporarily resolve the issue. Remove all food, transfer it to a cool box or insulated bag with ice packs to keep it frozen, and leave the freezer door open for several hours to allow any accumulated frost to melt completely. Place towels around the base to absorb water.
Once fully defrosted, restart the appliance and monitor whether it returns to the correct temperature. If the freezer performs correctly for a few weeks after manual defrosting but then gradually warms again, this is a strong indicator that the automatic defrost system has failed and requires repair to prevent the cycle from repeating.
Never use a heat gun, hair dryer, or sharp implement to speed up defrosting. Heat guns and hair dryers risk damaging internal plastic components and create a burn hazard. Sharp implements can puncture the evaporator coils, which will cause a refrigerant leak and render the appliance irreparable. Allow defrosting to occur naturally.
Step 5: Listen for the compressor
With the freezer running, listen for the sound of the compressor. It produces a low hum or gentle buzz that should cycle on and off periodically. If the appliance is completely silent with no compressor noise at all, the compressor or start relay has likely failed and engineer attendance is required. If the compressor is running continuously without pause, the appliance is struggling to reach or maintain temperature and an engineer should investigate the cause.
Step 6: Check for an error code
Many modern fridge freezers display an error or fault code on their digital display when a system fault is detected. If you see a code alongside the temperature problem, look it up in your appliance manual or through our appliance error codes guide before proceeding. The code will often identify the specific component that has failed and give you a much clearer picture of what the repair involves.
Freezer not freezing: quick diagnosis by symptom
| Symptom | Most likely cause | First check |
|---|---|---|
| Freezer slightly warm, food soft but not thawed | Temperature set too warm, or partial door seal failure | Check settings, test door seal with paper |
| Freezer warming gradually over days or weeks after working normally | Frost build-up blocking evaporator airflow | Manually defrost and monitor |
| Freezer warm, fridge also warmer than normal | Compressor fault, refrigerant leak, or shared evaporator frost blockage | Check for error code, call engineer |
| Freezer warm, fridge running cold | Damper fault, freezer fan failure, or freezer-specific seal issue | Check freezer door seal, listen for fan noise |
| Compressor running continuously, freezer not reaching temperature | Door seal failure, refrigerant leak, or dirty condenser coils | Check seal, check condenser coil cleanliness |
| Completely silent, no compressor noise at all | Compressor or start relay failure, or power supply fault | Check power, then call engineer |
| Heavy frost on rear or side wall inside freezer | Door seal failure allowing moisture in, or defrost system fault | Check seal first, then defrost and monitor |
| Freezer working, then stops after manual defrost restores function | Defrost heater, thermostat, or timer failure | Engineer required to replace defrost component |
| Error code displayed alongside temperature problem | Specific component fault indicated by code | Look up error code, then assess repair options |
What can I fix myself and what needs an engineer?
Checks and repairs you can do yourself
- Adjusting the temperature setting
- Testing and replacing a faulty door seal
- Manually defrosting the freezer to restore short-term function
- Cleaning dusty condenser coils
- Checking the location and improving ventilation clearance
- Identifying error codes and using them to inform a repair decision
- Replacing a start relay on some models if confident with basic appliance repair
❌ Repairs that need a professional engineer
- Replacing a failed evaporator fan motor
- Replacing a defrost heater, defrost thermostat, or defrost timer
- Diagnosing and repairing a compressor fault
- Refrigerant leak detection and recharging – requires specialist equipment and must only be carried out by a qualified engineer
- Replacing a temperature sensor or thermistor
- Repairing or replacing a damper motor in a fridge freezer
Is it worth repairing a freezer that has stopped freezing?
Whether a repair is the right financial decision depends on the age of the appliance, the cost of the repair, and what a replacement would cost. As a general guide, if the likely repair cost exceeds 50% of the cost of a comparable replacement appliance, replacement is often the more sensible long-term choice, particularly for older appliances where other components may also be approaching the end of their service life.
However, simpler repairs such as a door seal replacement or a defrost heater are typically inexpensive and straightforward, and carrying them out on an otherwise healthy appliance is nearly always the right decision. Our full guide to repairing versus replacing a domestic appliance covers the decision in more detail and gives you a framework for working out which makes financial sense for your specific situation.
Under the UK’s Right to Repair regulations, manufacturers of domestic refrigeration appliances are required to make spare parts available for a minimum of seven years after the product is manufactured. This means that for most freezers less than seven years old, genuine spare parts should be available for a repair. See our guide to the right to repair white goods for more detail.
Always switch the freezer off at the socket and unplug it before checking internal components such as the evaporator fan or door seal mechanism. Do not use sharp tools to remove ice from inside the freezer. Refrigerant handling must only be carried out by a qualified engineer with specialist equipment. If your appliance shows signs of burning, a burning smell, sparking, or any damage to the power cable, do not attempt any inspection and seek professional advice immediately. See our DIY appliance repair safety guide before attempting any hands-on work.
Freezer still not freezing after working through these checks?
If the simple checks have not resolved the fault, a component failure is likely. Our engineers cover fridge freezer and freezer repairs across all major brands nationwide. We also stock genuine spare parts including door seals, defrost heaters, evaporator fans, and thermostats for most models.
Frequently asked questions about a freezer not freezing
Why has my freezer suddenly stopped freezing?
A sudden change in freezer performance, rather than a gradual decline, is most commonly caused by a door seal that has failed allowing warm air in, an evaporator fan that has stopped running, a compressor start relay failure, or a power supply interruption that has caused the appliance to restart in a different mode. Check the temperature setting first, then inspect the door seal. If the seal and settings are both correct, the fault is likely internal and will require an engineer to diagnose properly.
Can a freezer be too full to freeze properly?
Yes. Overfilling a freezer, particularly with warm or room-temperature food added all at once, can temporarily raise the internal temperature beyond the appliance’s capacity to cool quickly. However, a correctly functioning freezer should recover within a few hours of being loaded. If the appliance cannot reach -18°C even when loaded normally and given time to recover, there is an underlying fault rather than an overfilling issue. Overfilling can also restrict airflow inside the freezer compartment, which impairs temperature distribution. Always leave some space for air to circulate between items.
How do I know if my freezer door seal needs replacing?
Test the seal by closing the door on a piece of paper and pulling it out gently. If the paper slides out without significant resistance, the seal is not creating an airtight closure at that point. Repeat the test around the full perimeter. Also inspect the seal visually for tears, splits, perishing, flattening, or sections where it has pulled away from the door. A seal that has lost its shape through age can sometimes be restored temporarily by warming it gently with a hair dryer held at a safe distance to restore flexibility, but a seal in poor condition should be replaced. Replacement seals are available for most major brands.
My freezer runs constantly but never gets cold enough. What is wrong?
A freezer running continuously without reaching the target temperature is typically trying to compensate for either warm air entering the compartment or heat that cannot be efficiently released from the system. Common causes include a faulty door seal, a refrigerant leak, dirty condenser coils preventing heat release, or a defrost system failure causing ice to accumulate on the evaporator coils. Check the door seal, check the condenser coil cleanliness, and if the appliance has been running for more than 24 hours without reaching temperature, call an engineer as a refrigerant fault is possible.
Can I use a freezer that is not freezing properly?
You should not rely on a freezer running above -18°C to safely store frozen food. Food in a freezer running between -10°C and -15°C will remain frozen but will deteriorate more rapidly than at the correct temperature, and some products may begin to thaw partially. Food that has partially thawed should not be refrozen without cooking first. Use a freezer thermometer to check the actual temperature and if it is running above -18°C, address the fault promptly. See our guide to what to do if your freezer stops working for advice on protecting food during a breakdown.
Is a freezer not freezing covered by my consumer rights?
If your freezer has developed a fault within the first six years of purchase, you may have rights under the Consumer Rights Act 2015, even if the manufacturer’s guarantee has expired. For a fault that develops within the first six months, the burden of proof is with the retailer to demonstrate the fault was not present at the time of sale. After six months, the burden shifts to you to show the fault is inherent rather than caused by misuse or wear. Our guide to your rights under the Consumer Rights Act covers this in full.