De quanto em quanto tempo devo descongelar o congelador?

Num modelo sem No Frost, quando o gelo nas paredes chegar aos 3 a 5 mm. Para muitas casas, isso significa entre uma vez por mês e duas ou três vezes por ano, conforme as vezes que a porta é aberta e o estado dos vedantes. Nunca deixe passar de 1 cm.

Posso usar o secador de cabelo para acelerar?

Não. O calor concentrado pode rachar ou derreter os plásticos interiores, e um aparelho elétrico junto de água corrente traz risco de choque elétrico. Se quiser acelerar, use recipientes com água morna e a porta aberta, e uma ventoinha do lado de fora.

Quanto tempo posso ter a comida fora do congelador?

Depende do isolamento. Numa geleira com acumuladores de frio, e com os alimentos embrulhados em várias camadas de papel, a comida aguenta bem as horas de um degelo normal. Se um alimento ainda tiver cristais de gelo quando o arrumar, pode voltar a ser congelado.

Porque é que o meu congelador ganha gelo tão depressa?

As causas mais comuns são vedantes gastos ou sujos, aberturas frequentes da porta, alimentos guardados ainda quentes e uma temperatura mal regulada. Comece pelos vedantes e confirme que o termóstato está perto dos -18 °C. Se o aparelho for No Frost e mesmo assim acumular gelo, contacte a assistência da marca.

Back to the journal

9 November 2026

How to Safely Defrost Your Freezer, Step by Step

To defrost your freezer without damaging the appliance or the food, start the day before: lower the temperature to create a cold reserve. On the day, transfer the food to a thermal bag and unplug the appliance. Leave the door open, with towels on the floor and a container of warm water inside, and only remove the ice that has already loosened with a plastic spatula. Then clean, dry, plug it back in, and wait for the freezer to reach -18 °C again before putting everything back. Expect a few hours, longer if the ice is thick. Below we explain each step, how long it takes, what to never do, and how to prevent ice from forming quickly again.

In Summary

Defrost when the ice on the walls reaches a few millimeters: Electrolux Portugal suggests 3 to 5 mm as the right time.
Always unplug, leave the door open, and speed up the process only with containers of warm water. No hairdryers, heaters, steam, or knives.
The time varies greatly with the thickness of the ice: from about 2 to 24 hours.
Plug it back in at maximum cold and only put the food back when the inside is cold again, ideally at -18 °C.
Well-sealed door, full freezer without overcrowding, and nothing warm inside: this is how to slow down ice formation.

Index

When is it time to defrost
What to prepare before starting
Defrosting the freezer: the right steps
How long it takes
What you should never do
Food during defrosting
Clean and plug back in
Is it possible to defrost without unplugging?
How to prevent ice from forming quickly again
Our vision: the freezer is also part of a well-kept home
When the freezer is part of a larger clean
Frequently asked questions
Sources

When is it time to defrost

Ice forms because every time you open the door, humid air from the kitchen enters. This moisture freezes on the walls and, layer by layer, turns into a crust that takes up space in the drawers and forces the motor to work harder. EDP indicates that this layer of ice can increase the refrigerator's consumption by up to 5% and hinders the cooling of food.

Manufacturers give slightly different references, but all point in the same direction: do not let the ice thicken.

Reference	When to defrost
Electrolux Portugal	When the ice on the side walls reaches 3 to 5 mm
Beko Portugal	About once a month, or when the ice reaches 0.5 cm, in models without No Frost
Hisense Manual	Two or three times a year, with about 4 mm of ice
Electrolux Chest Freezer Manual	Never let it exceed 1 cm, as ice acts as an insulator

In practice, the frequency depends on how often the door is opened, the humidity of the house, and the condition of the seals. In a family home in Lisbon, with the freezer opened several times a day, the crust grows much faster than in a holiday home that remains closed for weeks. The most reliable signal is visual: if the drawers start to stick or if you see a continuous white layer on the walls, it's time.

Choose the moment wisely. Electrolux reminds us that it is easier to defrost with the freezer empty or nearly empty, so ideally plan the task for after a week when the reserves have been used up. A cool morning helps: food holds up better outside the appliance.

What to prepare before starting

Preparation starts the day before. Electrolux Portugal recommends lowering the temperature about 12 hours in advance, so that the frozen items gain a cold reserve and withstand better the time outside the appliance. Some manufacturers suggest shorter timeframes, around 6 hours, but 12 hours give you more leeway.

Have ready:

Thermal bags or a cooler, with cold packs, for the food.
Newspaper or paper to wrap the frozen items in several layers, as suggested by Electrolux. Paper insulates well.
Old towels for the floor and the base of the freezer.
A tray or shallow basin to collect the draining water, if your model has a drainage plug.
The plastic spatula that comes with the appliance, or one made of plastic or wood.
One or two heat-resistant containers for warm water.
Soft cloths, warm water, and neutral detergent for the final cleaning.

If the refrigerator is combined and has space, DECO Proteste suggests moving some of the food to the coldest part of the refrigerator. This works well for small amounts; for a full freezer, the cooler is safer.

Defrosting the freezer: the right steps

This is the method that manufacturers and DECO Proteste describe for freezers without No Frost technology:

Empty the freezer. Remove all food, wrap it, and store it in the thermal bag or cooler, in a cool place away from sunlight.
Unplug it. Remove the plug from the socket by pulling on the plug and not the cord, as indicated in the BSH manual. Simply turning off the button is not enough.
Remove drawers and shelves. If they are stuck by ice, wait for them to loosen and do not force them.
Protect the floor. Place towels at the base of the freezer and in front of the appliance. If there is a drainage plug, remove it and place the tray underneath.
Leave the door open. The kitchen air does the main work. Never defrost with the door closed.
Speed up with warm water. Place a container with warm or hot water on a shelf and change the water when it cools down.
Remove the ice that loosens. With the plastic spatula, push the plates that have already detached. If they resist, leave them for a few more minutes.
Collect the water. Change the towels and empty the tray whenever necessary, to avoid wetting the floor or furniture.

With wooden floors or built-in furniture, pay extra attention to the towels.

How long it takes

The honest answer is: it depends on the ice. Maytag indicates that defrosting can take from 2 to 24 hours, depending on the thickness of the layer on the walls. A freezer with 3 or 4 mm of ice, with the door open and warm water inside, is usually ready in a morning. A chest freezer with several centimeters of ice accumulated over the years can take the whole day.

What shortens the time, without risks:

Containers with warm water, refreshed every half hour.
A fan pointing inside, at a safe distance and always outside the appliance, also suggested by Maytag.
Removing the ice as it loosens, so that the lower layers are exposed to the air.
Defrosting regularly. This is the most effective way to save time: the thinner the layer, the faster the process.

What you should never do

Tricks circulating on social media promise results in minutes, but some put the appliance and the person defrosting it at risk.

Practice	Why to avoid
Hairdryer or heater	DECO Proteste warns that thermal shock can crack or melt surfaces and that water and electricity together pose a risk of electric shock
Steam cleaning machine	The BSH manual prohibits it due to the risk of short-circuiting and electric shock
Knives, screwdrivers, or sharp objects	They can puncture the refrigerant gas lines; according to the BSH manual, the released gas can ignite or injure the eyes
Forcibly pulling off ice plates	Can break plastics, drawers, and the interior walls
Defrosting with the door closed	The Electrolux manual expressly advises against it

If you accidentally puncture the circuit and hear a hissing sound or smell something strange, unplug everything, ventilate the kitchen, keep flames away, and call an appliance repair technician before plugging the appliance back in.

Food during defrosting

With the cold reserve from the day before, the well-sealed cooler, and the freezer defrosted in a few hours, most food returns to the freezer still solid. The food safety rule from the USDA is clear: food that still has ice crystals or has been kept at 4 °C or less can be refrozen.

If something has completely thawed and has been at room temperature, do not refreeze it raw. Meat, fish, and cooked meals in that state should be cooked and consumed, or thrown away if there is doubt about how long they have been warm. In case of doubt, especially with babies, pregnant women, the elderly, or people with weakened immune systems at home, it is better to throw it away.

The same criterion applies to an unexpected power outage. The USDA indicates that a full freezer maintains temperature for about 48 hours, and 24 hours if half full, as long as the door remains closed.

Clean and plug back in

When the ice is gone, take the opportunity to clean the interior. The BSH manual recommends a soft cloth, warm water, and a neutral detergent, being careful not to let water enter the lighting. To eliminate odors, the Electrolux manual suggests a solution of one tablespoon of baking soda in one liter of water.

Then:

Dry everything very well, walls, drawers, and door seals. Any remaining moisture will turn into the first ice of the next cycle.
Replace the drainage plug, if you removed it.
Turn the freezer back on and set the thermostat to maximum cold.
Wait before putting things back. Electrolux Portugal indicates at least three hours at maximum cold before putting the food back, and DECO Proteste recommends waiting for the appliance to return to -18 °C.
Organize and adjust. Place the food back, close the door, and a few hours later, return to the usual temperature.

Take the opportunity to review what you have: label the boxes with the date, put the items that need to be consumed first at the front, and throw away anything that has lost quality.

Is it possible to defrost without unplugging?

In a conventional freezer, not safely. Tricks involving aluminum foil or boiling water with the appliance on combine heat and water with an operating electrical appliance. Manufacturers and DECO Proteste agree: unplug it.

The exception is appliances with No Frost technology. Whirlpool describes it as a solution that reduces humidity and prevents ice accumulation, eliminating the need for manual defrosting. In these models, cleaning the interior is done with the appliance unplugged, but without waiting for defrosting. If you have a No Frost appliance with ice accumulation, the problem is usually something else, like a worn seal or a defect, and it is best to contact the brand's technical support.

How to prevent ice from forming quickly again

Beko Portugal summarizes the precautions that make the most difference:

Open the door as little as possible and close it immediately. EDP estimates that each opening can represent up to 15% of the refrigerator's consumption.
Check the seals. Close the door over a sheet of paper: if it slides easily, the rubber may need cleaning or replacement.
Keep it about 3/4 full. An overly empty freezer fills with humid air with each opening; an overly full one does not allow cold to circulate.
Never store hot food. Let it cool first, so it doesn't release steam inside.
Check the temperature, recommended at around -18 °C.
Pack food well, in boxes or sealed bags, to reduce humidity inside.

Our vision: the freezer is also part of a well-kept home

In the homes we clean in Lisbon, we often see that the freezer is the task that always gets postponed to the following week. We understand why: it requires planning, free time, and a morning without rush. For a busy family, that rarely exists.

Our way of working is based on detailed checklists, room by room, and standards that do not change depending on the professional who comes to your home. It is this logic that we also recommend for the freezer: to turn it into a routine with a set date, rather than an emergency when the drawers stop closing.

There are two moments when this weighs more. The first is moving: those leaving a rented apartment want to deliver the kitchen spotless, and an unfrosted freezer is one of the details that stands out immediately. The second is the holiday home or second residence, which remains closed for weeks and needs to be prepared before the next occupants arrive.

In both cases, our advice is simple: defrost and empty the freezer the day before and leave the rest of the house to us, with the same team and the same standards as always.

Taras

When the freezer is part of a larger clean

If you are preparing for a move, welcoming new tenants, or simply want to recover the kitchen and the rest of the house at once, Cleaning Point takes care of that in Lisbon. Our deep cleaning follows a detailed checklist, and the move-in and move-out cleans leave the house ready for those arriving.

Cleaningpoint

You can add extras like oven and appliance cleaning, windows, or balcony, charged separately, and see all options on our cleaning services page. When you want to proceed, book your cleaning online.

Frequently asked questions

How often should I defrost the freezer?

In a model without No Frost, when the ice on the walls reaches 3 to 5 mm. For many homes, this means between once a month and two or three times a year, depending on how often the door is opened and the condition of the seals. Never let it exceed 1 cm.

Can I use a hairdryer to speed it up?

No. Concentrated heat can crack or melt the interior plastics, and an electrical appliance near running water poses a risk of electric shock. If you want to speed it up, use containers with warm water and keep the door open, along with a fan outside.

How long can I keep food outside the freezer?

It depends on the insulation. In a cooler with cold packs, and with the food wrapped in several layers of paper, food holds up well during a normal defrosting period. If a food still has ice crystals when you put it back, it can be refrozen.

Why does my freezer gain ice so quickly?

The most common causes are worn or dirty seals, frequent door openings, food stored while still warm, and poorly regulated temperature. Start with the seals and check that the thermostat is near -18 °C. If the appliance is No Frost and still accumulates ice, contact the brand's support.