Screen wash in the AdBlue tank
Screen wash in the AdBlue tank is dilution and contamination rather than hydrocarbon poisoning, so it is usually recoverable by drain and flush. Do not run the engine if you can avoid it. Call 01295 380724.
Screen wash is mostly water with alcohol, surfactants and dye. It is not a hydrocarbon, so it does not coat the circuit the way diesel does — but it is nothing like AUS 32 either. The urea concentration drops out of the 32.5% specification, the alcohol and surfactants are not meant to be dosed into a hot exhaust, and the dye and detergent leave residue. Vehicles with a fluid-quality sensor will usually flag it; ones without will simply dose the wrong thing.
Call 01295 380724 From just £89 call-out fee
Screen wash in the AdBlue tank — the severity verdict
| Severity | Likely recoverable Usually resolved by a drain and flush, with a fluid-quality check afterwards. |
|---|---|
| What went where | Screen wash in the AdBlue tank |
| Direction | Into the AdBlue tank |
| Typical cost | £180–£380 typical total, from a £89 call-out |
| Time on site | About 70 minutes |
| Call-out | From just £89 call-out fee |
| Helpline | 01295 380724, 24 hours |
£89 is the call-out. An AdBlue tank drain and flush is quoted on the phone before a technician travels. If the SCR system needs component replacement — dosing injector, pump, tank or catalyst — that is separate, and you will be told before any work starts. If this is a job we cannot fix at the roadside, we will tell you that on the phone rather than after we arrive.
What to do right now
- Avoid running the engine — every minute of running doses contaminated fluid into the exhaust.
- Do not top up with AdBlue to bring the concentration back. The specification is a formulation, not an average.
- Call 01295 380724.
What a technician actually does
Full drain, flush with demineralised water, flush with fresh AUS 32, refill with ISO 22241 fluid, fault codes read and cleared, and a dosing test.
Why this is not the same job as the other direction
This is contamination of the SCR dosing circuit — tank, metering pump, heated lines, dosing injector and potentially the catalyst. It is not the fuel system, and it is not the cheaper job. Anyone quoting a flat drain price for this has not looked at the system.
Common questions
Can I fix the concentration by adding more AdBlue?
No. AUS 32 is 32.5% urea in demineralised water — a specification, not a target you can average your way back to with alcohol and surfactants in the tank.
Will the system detect it?
Many vehicles carry a fluid-quality or NOx-conversion check that eventually flags it, but often only after several driving cycles, by which point contaminated fluid has been dosed.
Is this as bad as diesel in the AdBlue tank?
No, and it is priced differently. This is normally a drain and flush with a fluid-quality check afterwards.
What customers say
4.8 out of 5 from 2,190 Trustpilot reviews. What reviewers mention most is that the technician stayed calm and professional with a driver who was embarrassed and stressed, and that somebody arrived when they said they would.
The most common criticism is price. People do not expect a wrong-fluid job to cost what it costs, and that is a fair complaint to publish rather than bury. The answer is the From just £89 call-out fee, a quote given on the phone before a technician travels, and being told when a job cannot be done at the roadside rather than after somebody has arrived and charged for the visit.
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Where we cover
Who you are dealing with
This site is published by Forecourt Assist, which operates AdBlue in Fuel. Forecourt Assist is a trading name of Fuel Fixer Ltd, company no 08520551, registered at Fairway House, Portland Road, East Grinstead, RH19 4ET, a company of Fuel Fixer International. The group, Fuel Fixer International, is owned by Stockbridge Capital Holdings.
Reference: DVSA — roadworthiness guidance.
Across the Fuel Fixer network
Every brand above belongs to Fuel Fixer International, owned by Stockbridge Capital Holdings. The directory lives on the operator's own site: forecourtassist.co.uk/network.