When rushing to get on the road on an ice-cold wintery morning, the last thing you want to do is defrost your car windows.
However, reduced visibility can cost lives, and partial defrosting is not a safe solution. You could risk an on-the-spot fine and penalty points if you do not completely clear the ice, frost or snow-covered windows before setting off.[1] Rule 229 of the Highway Code requires a clear, unobstructed view of the road.[2]
So, don’t let a frosted or fogged-up car make you late or unsafe. Follow our tips for defrosting your car; and you’ll have clear visibility plus some warmth in no time.
EASY AS HACK
Prevention is always best. Put a shield across your windscreen when foggy, icy or snowy weather is forecast.
At a glance
The best ways to defrost your car windows and windscreen on a frosty, icy or snowy day are:
- Heating the interior
- Using de-icer spray
- Scraping the car
- Covering the windscreen
how to defrost your car windows and windshield
When temperatures drop and your vehicle is outside, you’ll likely need to thoroughly defrost the windows and windshield before leaving.
Some modern EVs and hybrids allow you to defrost your car remotely from an app.[3] However, if you own a diesel or petrol vehicle, you usually have to manually defrost the windows and windshields from inside or use automatic climate control.
Start by putting on a coat and gloves to keep warm. The warmer you are, the less tempted you are to create a gap to see through, or ‘porthole’ and drive off before you have de-iced the car entirely.
Ensure your wipers aren’t on
- If you’re considering using your wipers to remove the ice? Don’t! You can damage the wipers if they freeze to the glass
- Switching the wipers on while defrosting the car is a bad idea for the same reason.[4]
Start the engine
- Get into your car and turn on the engine
- If your vehicle has manual climate control, turn on the warm air blower/fan
- Increase the fan speed to high[5] and turn the temperature to the highest setting
- Turn on the air conditioning alongside the heating, as it will remove and dry any moisture[6] – speeding up the process. Some cars do this automatically when you select defog/defrost
- If the window is misted inside, use a lint-free cloth, not your hands.
Turn on defog/defrost
- Most cars have a button or a dial that you press or turn to defog or defrost ice from the windscreen and windows using warm, dry air
- Turn the dial or press the button
- To find the rear windscreens defog/defrost button, look for a rectangle window shape with three upward wavy arrows
- The front windscreen defog/defrost symbols also have three wavy arrows but are against a curved window shape.[7]
Adjust the temperature and fan settings
- Turn the temperature up to the highest setting to warm the glass and speed up defrosting [5](it will increase independently if you have automatic climate control)
- Set the fan to maximum power so as much air as possible spreads across the glass
- Use any thumbwheels to open vents and adjust the direction of the airflow
- Target the windscreen and side windows by turning the vents towards them (don’t worry about the rear windscreen as it contains electric elements that will melt the ice or dry any fog or condensation).
Sweep off the snow
- While you’re waiting for the car to defrost, sweep away any loose snow from the vehicle
- A soft handheld brush[8] is handy for removing any snow from the glass and the bonnet
- Some ice scrapers include a snow brush at the other end.[9]
Use a scraper and de-icer
While the car’s inside warms up, here are a few more tips to help speed up the de-icing process:
- Spray the side windows and rear windscreen with de-icer fluid (bought or made) before using an ice scraper. Bought de-icer sprays are affordable but contain chemicals
- To make your de-icer at home, mix a third of water with one-third of white vinegar and spray it from a spray bottle
- Use an ice scraper explicitly made for car windows and windscreens
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- Manual scrapers come in various shapes and sizes, including acrylic glass, plastic, rubber, or polycarbonate. Most ice scrapers have a handle.
- There are also electric ice scrapers that are rechargeable or heated
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- Wait until the heating, scraping and de-icing have completely cleared the windows and windscreens before setting off on your journey
- Don’t apply cold, lukewarm and especially hot water as they can all crack your windscreen and refreeze fast
- Don’t drive off until the glass is clear.
what do you need to defrost your car?
The main tools you need to defrost your car are the following:
- A soft bristle brush to clear away snow and ice
- De-icing spray to give the defrosting process a helping hand
- De-icing scraper to gently remove the ice
common mistakes when defrosting your car windows
These online car window ‘hacks’ are the common mistakes people make when defrosting the car.
- Hot water in a bag – some suggest filling a ziplock bag with warm water and rubbing it across ice[10] to melt it. However, you must never use hot water, which could crack the glass. We advise against using even warm water as it can refreeze
- Half a potato – you may have heard that rubbing a windscreen with a potato will prevent fogging. The downside is that the sticky starch it produces will smear your windscreen and impair visibility.
Other mistakes to avoid include:
- Using hot water
It is not advisable to use hot water because the rapid temperature change (known as thermal shock) can cause the glass in your windscreen to crack, especially if you have a chip. This hack is also unwise because hot water can refreeze fast,[10]creating more ice and taking more time to clear.
Find out more about How to avoid windscreen damage
- Using tools not designed to be a scraper
Alternative tools like a credit card or CD case could scratch your windscreen, so it’s best to avoid using them.
- Leaving your car running and unattended
It’s tempting to stay warm inside while you’re defrosting the vehicle. However, not only is there a risk that an opportunist could drive off in your car, but it’s also bad for the environment, and you could invalidate your insurance.
Find out What happens when you leave your engine running in cold weather.
Learn more about Ageas Car Insurance.
FAQs
is it safe to use warm water to defrost your car?
Using warm water to defrost your car is unsafe, as the glass expands when water touches it. It will also contract quickly as it cools down in the cold air. This flexing can make the glass crack.
Warm water refreezes faster than cold water, which could recreate a layer of ice on your windscreen. Never use hot water to defrost your windows and windscreen.
do you legally need to de-ice your car?
Yes, you need to de-ice your car by law. It is an offence as it can dangerously obstruct your view of the road if there is ice or mist on your windscreen. You could get a £100 fine and 3 points on your licence.
how to quickly defrost your car
- Ensure heaters and fans are on high
- Ensure the temperature is up
- Turn off the recirculated air
how long does it take to defrost a car?
It can take up to 10 minutes to defrost a car, but this depends on several factors, like:
- How quickly your car heats up
- How much ice is on the car
how long does it take to defrost a car?
You can avoid defrosting a car by ensuring the windscreen doesn’t freeze overnight. The simplest solutions are:
- Put a frost shield or cover across your windscreen – you can get them from car accessories shops (they can also cover your wing mirrors)[11] or make them out of cardboard[12]
- Use a garage if you have one or if you have a driveway, park your car close to your house on the drive. The shelter and heat from your home could help.
how to remove ice from the inside of your windscreen
Sometimes, ice can form inside your windscreen in freezing temperatures.
The best way to remove ice from the inside is the same as the outside: turn on the engine, fans and heating systems and carefully scrape away the ice.
Sources
[1] Don’t make defrosting vehicles an easy target this winter
[2] Driving in adverse weather conditions
[3] Defrost Your Car From Your Phone
[4] How to de-ice your car windscreen
[5] Defogging and Defrosting the Windshield
[6] How to demist your windscreen quickly - 3 Steps to a Clear Windscreen
[7] 12 important features in your car (some you probably don’t know)
[8] 24 Essential Winter Car Hacks
[9] The best car ice scrapers for clearing frost, snow and ice quickly and effectively
[10] Defrost Your Windscreen Quickly With These Top Tips
[11] Car Covers & Windscreen Shades
