For many drivers, car maintenance jobs such as filling up with screen wash are something other people do. According to various polls, anywhere between a third and a half of drivers struggle when it comes to even basic tasks to keep their car fit and healthy.

But there are some jobs that are key to safe driving and remarkably straightforward to do. Topping up the screen wash is one of those. To react safely to hazards ahead, you need to be able to see them. That's why this simple liquid is so vital.

It’s so important that not having any is sufficient reason for a car to fail its MOT.

Here’s how to put screen wash in your car.


How to Put Screen Wash in Your Car

  1. Dilute the screen wash with water, following the instructions on the bottle. The concentration is affected by the temperature, so follow the guidance closely.
  2. Once you've found the reservoir, open the cap.
  3. Using a funnel, pour the screen wash mixture into the reservoir until the liquid reaches the maximum line.
  4. Close the cap.

If you've mixed up too much liquid, either top up another car or pour the leftover into a plastic bottle. As long as the cap is tightly sealed and the liquid is stored safely, you'll always have an emergency bottle of pre-mixed screen wash on hand!


Where Is the Screen Wash Bottle and What Does It Look Like?

The screen wash bottle is located beneath the bonnet in the engine compartment. Its location differs from car to car. If you’re not sure exactly where it is, look in the user manual.

The bottle itself is frequently hidden away with the only visible parts being the cap and the bottle’s neck. The cap of the reservoir is frequently blue with a windscreen and wipers symbol on it.

However, the cap may be white or black.


How Do You Know When You Need To Top Up?

Modern cars will tell you when their screen wash is running low. As a full washer bottle isn’t fundamental to the car’s operation and running out won’t damage the car in any way, the reminder light is orange. It will usually illuminate when it’s running low rather than when it’s run out.

The size of the windscreen washer bottle, and therefore the frequency that it needs to be filled, varies depending on the make and model of car.

Family hatchbacks usually have between three and five-litre reservoirs.


Close up image of screen wash jets cleaning car windscreen

Using proper screen wash will prevent smearing and the washer jets getting blocked with limescale


Why Use Screen Wash?

It sounds obvious but the primary purpose of screen wash is to clean the windscreen.

Although water can technically do this, it won’t do so particularly effectively, a bit like washing up without washing-up liquid. Proper screen wash is formulated to remove the road grime, dead insects and dirt that windscreens get covered in.

If you don’t remove them – and water won’t ‑ you’ll end up with smearing on the screen.

In addition, it also includes water softener to prevent limescale building up in the pipework and tiny squirter jets.


How Much Screen Wash Should I Use?

It really depends on the time of year. Part of the function of screen wash is to lower the freezing point of the water in the reservoir.

In winter that temperature will need to be lower so the ratio will be higher.

What ratio for particular temperatures is detailed on the bottles.


Where Can I Buy Screen Wash From?

Screen wash is widely available from supermarkets, filling stations and DIY stores as well as motor retailers and online.

If you're having a problem with your windscreen washers, you can find a garage to put it right here.