Freezer not freezing in hot weather: what to check first

Quick answer: In hot weather a freezer has to work much harder to dump heat, so it can struggle if it sits in a hot garage, has dusty coils, a tired lid or door seal, or no room to breathe. Check the room temperature against the climate class on the model sticker, clean the coils, then check the seal, the fan and the thermostat. Food is holding if a thermometer in the middle reads about −18°C.

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Last updated October 2026

Is the freezer struggling, or is it the heat?

A freezer moves heat from inside the cabinet into the room. At 38°C there is far more heat pushing back in through the walls and seal, and far less difference between the hot coils at the back and the air meant to cool them, so a freezer that held −18°C all winter can drift to −10°C in a heatwave with nothing broken. The Bureau of Meteorology’s outlook of 1 October 2026 gives most of Australia a 60 to more than 80 per cent chance of above-average daytime temperatures to December (BOM climate outlooks).

The thermometer test. Put a fridge thermometer between packets in the middle of the load and read it after a few hours without opening the lid. About −18°C is right. Soft ice cream with hard meat means it is warmer than it should be but still below zero. Soft meat, or frost melting into a glaze, means it is above zero at times: work the check order now.

Check in this order (cheapest first)

Unplug the freezer before any panel, coil or fan work. Steps 1 to 5 cost nothing.

Freezer in the garage: read the climate class first

The usual summer freezer story: a chest or upright in the garage, fine for eleven months, then soft food in January. The climate class on the model sticker is the room temperature range it was designed for.

A tin-roofed garage can sit above 40°C from midday to evening on a severe heat day, and an N-class freezer in it will run without stopping and still lose ground. No part changes that. Shade, a door open for airflow, a fan across the back of the unit, or a move inside for the hot spell are what help.

Chest freezer or upright: different weak points

Chest freezers are simple: a compressor, a thermostat with a dial and a lid seal, usually with no fan and no defrost heater. When one stops holding temperature in heat, it is the room, the seal, the coils or the thermostat, in roughly that order. Frost on one section of the rim points at the seal there.

Frost-free uprights and the freezer side of a fridge-freezer add a fan behind the back panel and a defrost system. If the fan stops or the defrost fails, the coil ices into a block and the freezer warms even though the compressor runs non-stop. Those two parts most often turn a struggling freezer into a failed one.

Thermostat: the part that tells the compressor to stop and start

A thermostat that has drifted warm cycles the freezer off too early, so it never reaches −18°C. One that has failed open never calls the compressor, so the freezer warms in silence. One stuck closed runs the compressor non-stop. Our fridge and freezer thermostat replacement how-to covers the test with a multimeter and the swap. These are the chest and upright freezer thermostats we list by model. Match the full model code on your sticker against the listing title before you order.

Model on your sticker	Freezer type	Part listed for it
FR81T, FR91T	Westinghouse upright	Westinghouse upright freezer thermostat
RS-11DC4HA, RS-11DC4HNA	Hisense upright	Hisense upright freezer thermostat
FR90VN	Lemair upright	Lemair upright freezer thermostat
HR6CF206, HR6CF307	Hisense chest	Hisense chest freezer thermostat
HRCF200	Hisense 200 L chest	Hisense 200 L chest freezer thermostat
Chest and upright freezers with no model-specific thermostat listed	Universal	Chest and upright freezer thermostat (universal): read the listing’s fitting notes first
Frost-free fridge-freezers with the thermostat inside the freezer	Universal	Frost-free inside-freezer thermostat (universal)

The fridge-section thermostats for Samsung, LG, Westinghouse and Hisense fridge-freezers are in the sibling guide on a fridge running constantly in hot weather, and the full range is in the fridge and freezer thermostats category.

Freezer not freezing but the fridge is cold

In a fridge-freezer this is the reverse of the common fault, and it points at the freezer’s own airflow. Hold the door switch in and listen for the evaporator fan behind the back panel. Silence, or a scraping sound, means the fan has stopped or is iced in. Pull the back panel and look at the coil: a solid block of ice means the defrost system has failed and the fan cannot move air through it. Our guide on evaporator fan or condenser fan: which one your fridge has explains the two fans, and defrost heater replacement covers the heater. For the opposite case, a warm fridge section with a cold freezer, go to fridge not cooling but freezer works.

Model on your sticker	Brand	Part listed for it
HR6TFF459, HR6CDFF670S, HR6CDFF670B	Hisense	Hisense fridge fan motor
GF-V570MBL, GF-V570MBLC, GF-V570PNL, GF-VN500PL	LG	LG fridge evaporator fan motor

Other brands and models are in the fridge and freezer fan motors and defrost heaters categories.

Lid and door seals: the paper test

Close the lid or door on a strip of A4 paper and pull. Test the corners and the hinge side, where seals fail first. If the paper slides out with no grip, humid summer air is pouring in, and it shows up as a frost ridge at that spot and a compressor that never rests. Freezer seals are model-specific and we do not keep them on the shelf, so send us the code from your model sticker and we quote the seal for it. The door seal replacement guide covers the job on both fridges and uprights.

Compressor hot, clicking, or silent

A compressor that clicks, runs a few seconds and clicks off is tripping its overload: in heat, usually dirty coils or no airflow. If those are fine, the start relay on the side of the compressor is next, and it is a plug-in part. A compressor that runs hot and non-stop while the freezer warms, with everything above checked, points at the sealed refrigerant system, which needs a licensed repairer in Australia. Do not open the circuit. See fridge clicking noise and compressor not starting before buying a relay.

The power went off on a hot day: is the food safe?

Keep the lid or door shut. A full freezer holds its temperature far longer than a half-empty one, so fill gaps with bottles of water before a heatwave. Food that is still frozen hard, or has thawed but is still fridge-cold, can be refrozen or cooked. For anything that has warmed above 5°C, Food Standards Australia New Zealand’s 2-hour/4-hour rule applies: under 2 hours, refrigerate or use; 2 to 4 hours, use straight away; over 4 hours, throw it out.

Before the next hot spell: five minutes of prevention

• Read the climate class on the model sticker and decide now whether the garage freezer comes inside for severe heat days.
• Unplug and vacuum the coils before summer and again in January.
• Paper-test the lid or door seal at the corners.
• Fill empty space with bottles of water so the load holds its cold.
• Keep a thermometer in the load and look at it on hot evenings.

Frequently asked questions

Is it normal for a freezer to struggle in a heatwave?

Running longer is normal. Losing temperature is not. If a thermometer in the middle of the load still reads about −18°C after a hot afternoon, the freezer is coping. If it has drifted above −12°C, start with the room temperature, the coils and the seal, because those are free to fix.

Can I keep a freezer in the garage over summer?

Check the climate class on the model sticker: SN and N are rated to a 32°C room, ST to 38°C, T to 43°C. An uninsulated garage can pass all of those on a severe heat day, so an N-class freezer out there falls behind. Shade, airflow or a move inside are the fixes.

Why is my ice cream soft but everything else frozen?

Ice cream softens at a warmer temperature than meat or vegetables, so it is the first thing to show a freezer sitting above −18°C. Check the setting, switch fast freeze on for a day, clean the coils and test the seal. If it keeps happening in mild weather too, the thermostat is drifting.

My freezer is not freezing but the fridge is cold. What is it?

In a fridge-freezer that points at the freezer’s own airflow: the evaporator fan behind the back panel or a failed defrost system that has iced the coil solid. Hold the door switch in and listen for the fan, then pull the back panel and look for a block of ice.

Should I turn the freezer colder in hot weather?

Only if the thermometer says it is above −18°C. Turning the dial colder when it is already struggling makes it run longer for no gain. Fix airflow, coils and the seal first, then adjust.

The power went off. How long is frozen food safe?

Keep the lid shut and food that stays frozen hard is safe. Once anything has thawed above 5°C the FSANZ 2-hour/4-hour rule applies: under 2 hours back to cold or use it, 2 to 4 hours use it now, over 4 hours throw it out.

Get the right part first time

Search the model number from the sticker on the site, or send it through the contact page and we match it before you order. In-stock parts are dispatched from Sydney the day you order when it’s in by 12pm Sydney time. Oz Appliance Spares, Sydney’s Northern Beaches, Australian-owned since 2009.

Disclaimer: this article is general information only and is provided without warranty of any kind. Appliance designs vary between models and production runs — always follow the manufacturer’s instructions, switch off and unplug the appliance before starting any work, and confirm parts against the model number on your appliance’s model sticker. Any repair is undertaken at your own risk and Oz Appliance Spares accepts no liability for injury, loss or damage arising from work performed after reading this guide, to the maximum extent permitted by law. If in doubt, use a qualified technician.