How to defrost a freezer quickly and safely

A bowl of hot water and a closed door do most of the work.

The answer in 2 lines. Switch the freezer off at the wall and unplug it. Put the food in a cool box or cool bags with ice packs, or in the fridge. Put bowls of hot water inside and close the door: the ice loosens in big sheets. Never chip at the ice with a knife or sharp tool, and never use a hairdryer or heater near the water. Electrical Safety First advises defrosting at least once a year unless your freezer is frost free.

The first 3 steps

Switch off at the wall, unplug and empty the freezer. Put the food in a cool box or insulated bags with ice packs, or in the fridge.
Put towels on the floor and a tray or baking dish under the freezer, or use the drain outlet if the instruction manual says your model has one.
Put one or two bowls of very hot water inside, close the door, and swap in fresh hot water when it cools.

Stop: danger

Always unplug the freezer before you defrost it, and only plug it back in once it's completely dry inside and out.
No hairdryer, heat gun or heater: Electrical Safety First advises against using heating appliances to defrost. Near water, there's a risk of electric shock, and plastic parts can melt.
No knife or sharp tool: the cooling pipes run just behind the inner walls. If you hear hissing or smell gas after piercing one, open the windows, don't use flames or switches nearby, and leave it unplugged.

Speeding it up safely

Bowls of hot water with the door shut are the safest method: the steam softens the ice.
Lift the sheets of ice away by hand, or ease them off with a plastic or wooden scraper. Don't force them.
Mop up the water as you go and wring out the towels often.
It usually takes from one to a few hours, depending on how thick the ice is.

Getting it going again, and where to stop

Wipe the inside with warm water and a little washing-up liquid, rinse and dry thoroughly.
Plug it back in, wait until it's back at around -18°C (a freezer thermometer helps), then put the food back.
Sort the food as you go and label what you freeze (Food Standards Agency).
Food that has thawed: the Food Standards Agency says you can only refreeze food once it has been cooked.
Stop there if a frost-free model is icing up anyway. Its automatic defrost has probably failed, which is a job for a qualified repairer.

What not to do

Chipping the ice with a knife, screwdriver or ice pick: you can pierce the cooling pipes and ruin the freezer.
Using a hairdryer, heat gun or fan heater near the water.
Plugging the freezer back in while it's still wet.
Leaving the food at room temperature while you defrost: keep it cold the whole time.

When to call a repairer, and your rights

Call a qualified repairer if the ice comes back within days even though the door seal is fine, if a frost-free freezer ices up, or if the freezer won't get cold again after defrosting.
Faulty freezer bought from a business: within 30 days you can reject it for a refund. Within 6 months the seller must repair or replace it, and if that fails you can ask for a refund (GOV.UK). Normal wear and tear isn't a fault. Citizens Advice's Return faulty goods page has an online tool: answer its questions and it tells you what to ask the seller for.
Spare parts: for models covered by the UK's 2021 ecodesign rules, door gaskets must be available to the public for at least 10 years after the last unit of the model is sold, and door handles, door hinges, trays and baskets for at least 7 years. Parts such as thermostats and temperature sensors must be available to professional repairers for at least 7 years.

Where you live: getting rid of an old freezer

When you buy a new one: the seller must give you a free way to get rid of your old equivalent appliance, either in store or through an alternative free take-back service. Some offer collection when they deliver (GOV.UK). Ask before you order.
Otherwise, your council: on GOV.UK Recycling collections, enter your postcode to reach your council's page. It explains how to recycle large electrical items, at the household waste recycling centre or through a bulky waste collection.
Never leave an old freezer on the street: fridges and freezers have to be recycled properly.

Good to know

Unless your freezer is frost free, defrost it at least once a year (Electrical Safety First).
If ice builds up quickly, check that the door seal is clean, not split, and that the door closes properly.
Register your appliance with the manufacturer so you hear about any safety recall.
Electrical Safety First advises leaving your fridge freezer switched on when you go away. As it defrosts it leaks water, which is a fire risk.

In Derby, Hannah can no longer close the top drawer of her freezer. She puts the food in a cool box with ice packs, unplugs the freezer and puts two pans of very hot water inside. An hour later the ice is coming away in sheets. She dries everything, plugs the freezer back in and waits until it's back at -18°C before putting the food back.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 6 November 2026, for England. Confidence: high for the safety advice, the -18°C target, how often to defrost and the spare-parts rules; medium for how long defrosting takes and how the water drains, which depend on the appliance (follow the instruction manual).