How to defrost a windscreen - the hacks you definitely shouldn't try and the safest way to quickly de-ice a car

Time-saving hacks to defrost a frozen windscreen may sound appealing, but many doing the rounds on social media can lead to long-term damage and invalidate car insurance. And you don't want to be stuck footing the bill for a windscreen replacement if yours cracks. NimbleFins recently found that if car insurance doesn't cover the windscreen, the owner of a Nissan Qashqai (the most popular car of 2022) could pay from £900 to over £2,000 to replace it.

Using a kettle of hot water

Erin Yurday, co-founder and CEO of NimbleFins, said: "The most common harebrained idea is to use hot water from a kettle or straight from the tap and pour it directly onto the windshield. But this risks cracking the glass and also leaving you - not your car insurance company - footing the bill. It costs hundreds of pounds or more to replace a windscreen so it's worth being patient and not rushing for a costly quick fix."

Geoff Cudd, CEO and founder of Find the Best Car Price, called it "the biggest no-no".

He said: "The problem is that most windshields have a plastic coating to ensure that they don’t shatter on impact, and when warm water hits the frozen plastic layer, the temperature differential can cause the windshield to crack.

"And when you try to explain the problem to your car insurance company, and why it happened, they’ll politely tell you that as you’re the root cause of the problem and it was your fault, you’re going to have to dig deep to pay for a new windshield, as they won’t cover the bill."

Placing a zip-lock bag of warm water onto the windscreen

This latest TikTok craze has the same risk of pouring warm water directly onto the windshield.

Some on the social media site claim the hack works but this also could crack the windscreen and invalidate car insurance.

Pouring salt on the windscreen

Just because it works on the roads doesn't mean it's safe for a car. Salt is a big problem for engines, and can corrode metals five times faster than fresh water. The more salt a car is exposed to, the quicker the car parts will rust and weaken.

Salt can also harm the look of a vehicle.

Alex Booth, founder of WarningLightCo told NimbleFins: "Using salt on your windscreen can cause salt corrosion and can strip away the protective coating on your paint, affect your windshield wipers and screen spray, and can even affect smaller parts under the bonnet."

Using a hairdryer or portable heater

Want to find another way to crack a windscreen? Try blasting it with a hairdryer. Not only could this damage your car, but it could also put you in danger.

Alex added: "Not only is this dangerous as the moisture or water from outside could possibly create a spark with the hairdryer, but using a hairdryer or a portable heater can possibly create the same issue as using boiling water - there is a possibility of your windscreen cracking."

What we're saying here is windscreens are sensitive!

Metal scraper

When frost hits and you don't have an ice scraper in your car, it could be tempting to use anything you can lay your hands on.

But resist the temptation to use something metal.

Alex said: "Using anything metal on the screen can result in scratches that can impair your vision when driving or could even crack your windshield, leaving you to replace it."

If you do have an ice scraper, make sure it's plastic and not metal.

How to defrost your windscreen safely

Unfortunately there is no hugely quick fix to defrosting a car without the risk of damage, it is a case of turning your engine on, turning on the front and rear windscreen heaters and waiting. But our experts did give us one trick.

Before you switch the engine on, ensure the wipers are not set to come on automatically, otherwise you could damage the rubber or harm the wiper motor, the AA said.

Turning up the air con can speed things up, as can wearing a pair of gloves and placing your hands on the inside of the windshield.

Geoff Cudd said the only safe way to defrost the car is to let the motor get up to temperature and the hot air gradually clear the screen, but added: "The glove method actually speeds the process up and it’s safe, it works, and won’t crack your windshield.”