Frozen Screenwash and Washer Jets: Winter Fixes
Written by Petro Olekhnovych, mobile mechanic in Aylesham, Kent
On salty Kent roads in January, a windscreen goes from clear to grey in a mile. Without working washers you are smearing salt across the glass with every wipe, often straight into low sun. That is why frozen screenwash is a safety problem, not just an annoyance.
Why screenwash freezes
- Plain water in the bottle. Common after summer top ups. Water freezes at zero.
- Summer screenwash. Many summer mixes are for cleaning bugs off and offer little frost protection.
- Over-diluted winter wash. The ratio on the bottle matters. A weaker mix gives a higher freezing point.
- Exposed jets. Bonnet-mounted jets cool fastest, so they can block even when the bottle is fine.
Cars parked in open spots near the coast in Deal or Folkestone, or on high ground around Barham, often get the worst frost on the bonnet and jets.
How to thaw frozen washers safely
- Clear the windscreen properly first with de-icer and a scraper. Do not drive peering through a gap.
- Start the engine and run the heater on the screen. Do not leave the car running unattended while you go back indoors; besides the security risk, leaving an engine running unnecessarily while parked on a road can be an offence.
- As the engine bay warms, the bottle and pipes slowly thaw. Driving gently also helps once you can see clearly.
- When the washers work again, top up straight away with winter screenwash so it does not happen tomorrow.
Do not pour boiling or hot water on the jets, bottle or glass. A cold windscreen can crack from the sudden temperature change, and a brittle plastic bottle can split. Our guide on how to defrost a frozen windscreen covers the quick, safe methods.
Want to pass your MOT first time?
We do pre-MOT checks and fix advisories at your home or work across East Kent.
WhatsApp for a free quote Call 07563 350335 Contact form
Labour £30 to £50 per hour depending on the job. Send your reg number and we will reply with a price before any work starts.
Washer jets not working when it is not frozen
If it is a mild day and still nothing sprays, work through these simple checks:
- Listen for the pump. Have someone press the washer stalk while you listen near the bottle. A hum with no spray suggests a blockage or a split pipe. No sound at all points to a fuse, wiring or a failed pump.
- Check the fuse. The handbook shows which fuse runs the washer pump.
- Clear the jets. Wax, polish and grit block jets. A fine pin can clear the nozzle gently, but take care not to enlarge it.
- Look at the pipes. Pipes run under the bonnet lining and through the tailgate hinge for the rear washer. They can come off or crack.
- Check for a leak. If the bottle empties quickly, look for a damp patch under the front wheel arch, where many bottles sit.
Choosing winter screenwash
Buy a concentrate or ready mix that states its protection temperature, and follow the dilution chart on the label. For Kent, a mix that protects to around minus 10 or lower is a sensible margin for exposed jets, even though air temperatures rarely drop that far. Do not add washing up liquid, as it smears and does not lower the freezing point. Never put antifreeze from the cooling system in the washer bottle; it is a different product and can damage paint and rubber.
The law and the MOT
Highway Code rule 229 says you must be able to see out of every glass surface before setting off in winter, which includes clearing the windscreen of ice and dirt. At the MOT, the washers must work and supply enough fluid for the wipers to clear the screen. A dry bottle or blocked jets can mean a fail, so our pre-MOT check includes washers and wipers. Our winter car checklist covers the other quick checks. Worn blades make the problem worse, so look at our guide to wiper blades in winter too.
How we can help
At your home or workplace we can check the washer pump, fuse, pipes and jets, clear blockages, top up with the correct winter mix and check your wipers as part of a winter check or service. We cover Aylesham, Canterbury, Dover, Deal, Sandwich, Folkestone and surrounding villages. Labour is £30 to £50 per hour depending on the job, and we quote before any work starts. Send your reg and postcode on WhatsApp 07563 350335 or use our contact page.
Want to pass your MOT first time?
Message us on WhatsApp with your reg and postcode, or use our contact form, for a price before any work starts.
WhatsApp for a free quote Call 07563 350335 Contact form
Labour £30 to £50 per hour depending on the job. Send your reg number and we will reply with a price before any work starts.
Frequently asked questions
Can I pour hot water in the screenwash bottle?
No. Hot water can crack a cold plastic bottle and will refreeze on the jets and glass. Let the car warm up and use proper winter screenwash instead.
Is no screenwash an MOT fail?
Yes, the washers must work and provide enough fluid for the wipers to clear the screen. Top up before your test.
Why does only one washer jet work?
That usually means a blocked jet, a split or disconnected pipe, or on some cars a faulty one-way valve. If neither works, look at the pump, fuse or frozen fluid.
Can I use washing up liquid in screenwash?
It is best not to. It can smear, leave residue on paint and does not protect against freezing.
