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AA Ireland's tips for de-frosting your car AA Ireland's tips for de-frosting your car


AA Ireland's tips for de-frosting your car

Published 20th December 2021Read Time 7 min

It’s the moment we all dread: you’re already late, rushing out the door, tripping over kids and dogs and then you see it – a smooth crystal sheen across the windscreen. Maybe it’s condensation. You brace yourself and tentatively drag a finger across. No. Frost. Anything but frost.

You start to wonder how this morning could get any worse, and we’re here to tell you that it could. It could get so much worse. A lot can go wrong when you defrost your car incorrectly, but fear not. With the help of our colleagues at AA Rescue, we’ve laid out the dos and don’ts of defrosting. 


  • Open the car doors gently
  • We’ve all felt the resistance of a frozen car door on a particularly cold morning. The harder you tug, the more you risk damaging the door’s seal. Easy does it. If your car has a manual lock, it may become frozen too. Our colleagues at AA Rescue gave us this hot tip: heating the metal of your car key with a drop of hot water will melt any ice in the lock. The same rule goes for the doors though, take it easy and don’t force it.

  • Turn Off Your Wipers
  • Every time you turn off your engine, you should make sure that your wipers are down and switched off. If they’re left on, they will activate as soon as the engine starts. Frozen wipers can become damaged or even blow a fuse when they try to move. If your car has manual wipers, check the lever to ensure the wipers are off before starting the engine.

  • Start the Engine & Turn Up the Heat
  • Get the heater and rear windscreen de-mister going ASAP, using internal ventilation where possible. Check the heater is set to blow at the windows and turn it up full blast. It’ll take some time to heat up, especially on a very cold day, so be patient.

    NOTE: Cars in garages can also become frosted. Never leave the engine running in an enclosed space.

  • Sweep Snow From All Surfaces
  • While you’re waiting for the heater to work its magic, start sweeping snow (if any) off your car using a soft brush or cloth. Remember to clear the lights, roof, bonnet, wing-mirrors, registration plates and all windows. When you start to drive, snow can fall from the roof of your car and obstruct your view.

  • Spray & Scrape
  • Some days you’ll want to roll in with the big guns – de-icer. Spray de-icer at the top of your windows and allow it to trickle down and melt the ice on its way. Follow up with an ice-scraper to speed up the process.

  • Wait Until Your View is Completely Clear
  • Ensure your windscreen is fully cleared. Don’t take a chance – full visibility is essential, especially in hazardous conditions. You should also wait until the car is fully de-misted before opening any windows to prevent damage.

  • Be Prepared
  • If icy conditions are forecast, park your car in a garage or close to the wall of your house – the warmth of the house will help to prevent frost forming. It’s also a good idea to cover your windscreen with a shield or sheet of cardboard the night before. Set your alarm 10 minutes early in the winter to leave you enough time to defrost – it’s only stressful if you’re under pressure.


  • Don’t Leave your Alone Car With the Engine Running
  • Once you put the key in the ignition, stay by your car at all times. Car thieves love an icy morning and every winter cars are stolen while their owners go inside for warmth waiting for their car to defrost. It’s actually an offence to leave your car unattended with the engine running. You’ve been warned.

  • Don’t Use Hot Water
  • Step away from the kettle! Hot water on a frozen windscreen can crack the glass, especially if it’s already chipped. On a very cold day, hot water freezes quicker than cold and can create a fresh layer of ice on your car. In fact, even cold water can end up exacerbating the situation by freezing over too. Best to avoid the splash altogether.

    Similarly, never use boiling water to clear snow from your driveway – if it re-freezes you could end up with your very own ice-rink. Spread salt on a clear area the night before to help prevent it from freezing in the first place.

  • Don’t Clear Snow With Your Wipers
  • Wipers are delicate creatures, designed to clear rain from your windscreen – nothing more. On a wintery night, wipers themselves can become frozen to the windscreen. Switching them on to clear frost could tug at the rubber causing it to come away.

    Don’t forget it can take up to ten times longer to stop on icy roads – check out Met Éireann’s forecast for your area before heading out.