Where to put screen wash and how often to top it up

Tuesday 19th August 2025

Topping up your screen wash is a quick and easy task that’s often overlooked. If you’ve never done it before, you might be a bit unsure about where it goes – that’s why we’ve put together this simple guide to keep your windscreen squeaky clean.

Where does screen wash go?

The exact location of the screen wash reservoir varies depending on your car’s make and model. However, it’s usually easy to spot, so it’s hard to get it wrong!

First, pop open the hood of your car, as the reservoir is located under the bonnet. Look for either a water symbol or a windscreen symbol on a brightly coloured cap. This cap covers a translucent container which holds the screen wash fluid. You can also check your vehicle handbook if you’re still unsure.

How much screen wash should I use?

Screen wash fluid either comes pre-mixed or needs to be diluted with water. The amount of water required will vary depending on:

• Outside temperature
• Screen wash type
• Pollution levels

How to dilute screen wash for different weather and driving conditions

If you’re using screen wash that needs diluting, you’ll need a stronger concentration in the winter months. This is because screen wash freezes at a lower temperature than water, so if it’s too diluted it could freeze and crack your reservoir.

If you’re driving in dirty or dusty conditions, you might want to use a more concentrated mix for a stronger cleaning power.

When topping up, we recommend mixing the screen wash and water thoroughly in a clean container before pouring it into the reservoir.

The reservoir will have a max fill line. Smaller and more compact cars will hold less screen wash, usually between 1.5 and 3 litres, whereas bigger vehicles, like SUVs, can hold up to 8 litres. Check your vehicle manual to avoid mixing too much. 

When should I top up my screen wash?

You should check your screen wash levels monthly and before long journeys. Don’t wait until the reservoir is nearly empty – you don’t want to run out mid-journey!

Here are three signs you’re running low:

1. Low spray power: A weak spray is a sign that there’s not much fluid.
2. Noisy spraying sound: If the spray makes a spluttering or spitting sound, it may mean you’re down to the last dregs of screen wash.
3. Dashboard warning light: Some vehicles will have a light that alerts you when it’s time to top up.

Did you know?

You could fail your MOT if you don’t have enough screen wash! To pass, you must have clear visibility through your windscreen. Book your MOT together with your next service, and we’ll top up your screen wash fluid, so you don’t fail on something minor.

Setting out on a long journey?

Keep your vehicle in top condition and book a free 10-point safety check, we’ll even top up your screen wash for free if you make an online purchase. So, what are you waiting for? Find your nearest centre today.