If you’re like most drivers, you probably only top-up your screen wash when the warning light flashes, or when your wipers start smearing bugs and grime across the windscreen. It’s a job that often gets bumped to the bottom of the list. That is, until you can’t see where you're going.
However, waiting too long to refresh your car windscreen cleaner can actually compromise your safety, damage your vehicle, and hurt the environment. It’s not just about being able to see properly (although that’s vital!), it’s about making sure the product in your washer tank is still doing its job.
So, how often should you actually be changing or refilling your car’s windscreen cleaner? Here’s a deep dive from Screen Wash King: your specialists in environmentally friendly screen wash.
Why Screen Wash Isn’t a ‘Fill It and Forget It’ Product
Many drivers assume that once screen wash is in the tank, it’s fine until it runs out. In reality, screen wash can degrade over time, especially if it’s a diluted or pre-mixed solution.
Low-quality cleaners or those mixed with ordinary tap water can go stale, grow bacteria, or lose their cleaning power, especially if left sitting for months. In colder months, screen wash that isn’t winter-grade can even freeze in the lines or jets, damaging the washer system.
In short, old or poor quality screen wash can leave you with smeary windscreens and blocked jets. It can even cause corrosion in your washer system. That’s not something you want to discover when driving 70mph in a downpour or after a flock of pigeons has left their mark.
The Short Answer: How Often to Change It
Check and, if needed, replace or refill your car windscreen cleaner every 1–2 months, or at the start of each season. But like most things in motoring, the timing depends on a few variables:
Factors That Affect How Often You Should Refresh Your Screen Wash
1. How Often You Drive
Frequent drivers use up screen wash faster, especially those who do long commutes, drive on motorways, or travel through country roads where bugs, dirt and road spray are more common. If that’s you, your tank might run dry faster than you realise.
2. The Time of Year
Autumn and winter mean rain and mud, along with salt and more gunk on the roads. Summer brings insects and tree sap. Different seasons bring different kinds of windscreen grime, so it makes sense to top up or switch your cleaner accordingly.
Some winter-grade screen washes contain anti-freeze components, while summer versions are formulated to cut through insects and pollen. If you’re using a year-round formula like Screen Wash King’s eco-friendly screen wash, you’re covered either way. But it’s still a good idea to refresh your tank regularly.
3. The Quality of Your Cleaner
Premium products last longer and perform better. Screen Wash King’s tablets, for example, dissolve into a powerful, non-toxic solution that stays effective for months, but even so, they’re best when used fresh.
On the other hand, cheap, heavily diluted cleaners may lose potency or even go off. Some can even leave residues that clog your nozzles or smear across the glass.
4. Storage Conditions
If your car sits in extreme heat or cold, the cleaner in the tank may degrade faster. Stored screen wash in garages or sheds can also expire, especially if exposed to air, light or changes in temperature.
Signs You Need to Change Your Windscreen Cleaner
Even if your washer tank isn’t empty, there are some tell-tale signs that it’s time to start fresh:
- Smearing instead of cleaning: A good screen wash should wipe the windscreen crystal clear. If you’re left with streaks, your cleaner isn’t doing its job.
- Dodgy smells from the jets: This could indicate bacteria or mould in the tank. In other words, time to flush and refill.
- Slow or clogged jets: Gunky screen wash can leave residues that block your nozzles.
- Frozen jets in winter: Your solution may lack proper anti-freeze components.
Why It Pays to Stay Topped Up
Did you know, the ability to maintain a clean windscreen is a legal and safety requirement? According to the UK’s Highway Code and MOT regulations, your washer system must be working and able to clean the screen properly. If it’s not, you could face a failed MOT or even a fine.
But beyond the legal side, this is about being a responsible driver. Being able to see clearly keeps you, your passengers, and everyone else on the road safer.
A Better Way to Stay Clean
You don’t need to lug heavy 5-litre plastic bottles around every few weeks. Screen Wash King’s compact tablets offer a better way. Just drop one in a litre of water, pour it in your washer tank, and you're good to go.
- No single-use plastic
- Long shelf life
- Easy to store in your glove box
And because they’re biodegradable and non-toxic, you’re doing right by the planet every time you top up. Happy motoring. And keep your screen as clear as your conscience.