A child draws a smiling face in the ice on a car windshield.

The dos and don’ts of de-icing your windscreen

There are a few ways to efficiently melt ice on your windscreen – and a few you should definitely avoid. Here’s a guide.

By Shell on Jul. 14, 2022

Just getting out of bed in winter can be tough. And there are other challenges – like shuffling out to your car to find it all iced up. So how best to deal with it? Well, whatever you do, you should never just clear a small spot to peer through so you can get onto the road quicker. Aside from the obvious safety risks, Australian road-traffic laws oblige you to have a clear view of the road ahead, behind and to each side of your vehicle when you drive. Here's how to fix things when the ice hits – and how not to.

Do: Crank the HVAC system

Your car's heating, ventilation and air-conditioning (HVAC) system is designed to clear the windows, so start your car and crank it up – either by setting it to windscreen-defrost mode or, if it's not a fully automatic system, switching the air distribution to windscreen, turning up the heat and fan speed and flicking the air-conditioner and rear de-mister on. This will start melting the ice from underneath while you deal with it from the outside.

Don't: Leave your car unattended

Aside from risking theft or other unintended consequences, it's illegal to leave your car unattended while running.

Do: Check your wipers first

If your wipers have frozen to the glass and you try to operate them, the blades or wiper motor could be damaged. Always check they're not on or in 'auto' mode before you start your car.

Don't: Use hot or warm water

Hot water might melt ice but it also subjects cold glass to thermal shock and the risk of shattering. Even lukewarm water is a risk – your windscreen might not shatter but the sudden expansion could still make it crack, especially if it's already cracked or chipped. Warm water freezes quicker than cold water, too, so even if you don't damage your screen you could be just adding more ice.

Do: Use an ice scraper

Once the ice has started to melt, scape it off with an ice scraper using short, rapid strokes. When it's properly loose and you've got most of it off, use your wipers to remove the rest.

Don't: Improvise an ice scraper

While an old credit card will get the job done, you'll do it quicker and better with a store-bought ice scraper – they have a larger scraping area and handle so are easier to use, and they are cheap. If you absolutely have to use something from around the house, just make sure it's never metal – that'll get the ice off but also scratch your glass. And while it sounds obvious, never try to break the ice by tapping it lightly with a hard object – it's a sure-fire way to crack the glass as well.

Do: Use a de-icer

A de-icing product is an easy and inexpensive way to speed up the melting process. After firing up your car and HVAC system, simply spray on the solution, wait for it to work its ice-melting magic, then bring in the ice scraper.

Don't: Use a home-made de-icer

There are a lot of home-spun de-icing recommendations out there, from salt to a mix of water and vinegar or rubbing alcohol. All are effective de-icers but they are corrosive to your car's glass, paint, plastics and other delicate surfaces – unlike a store-bought solution, which is formulated not to do damage.


Viva Energy Australia Pty Ltd (“Viva Energy”) has compiled the above article for your general information and to use as a general reference. Whilst all reasonable care has been taken by Viva Energy in compiling this article, Viva Energy does not warrant or represent that the information in the article is free from errors or omissions or is suitable for your intended use.