--- title: Batford: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/batford-hertfordshire/ location: Batford county: Hertfordshire latitude: 51.824680 longitude: -0.340560 service: AdBlue in a Diesel Tank updated: 2026-10-17 --- # Batford: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? If AdBlue is already in your diesel tank, stop reading for a moment: leave your engine and your ignition off and call 0333 366 0103. Usually, when your motor hasn't run, it is drained and thoroughly cleaned where your car sits around Batford. Nothing happened yet? Further down, the page covers the why it occurs and the how to avoid it altogether. ## AdBlue in a diesel motor, and its separate tank Many modern diesels around Lea Valley, like those in Batford, carry on two fluids; your motor gets only your diesel. Stored in a tank of its own, AdBlue is fed into your exhaust gas to clean it. Different tanks, separate fillers. Some motors put the AdBlue filler in the boot or under the bonnet; a lot of others place both together under one flap. At the petrol pump, the diesel side is topped up constantly. Far less often, the AdBlue side is filled — normally from a bottle, by a person thinking about where it goes. The mistake lives in that gap. ## How AdBlue in the diesel tank happens in Batford Carelessness seldom explains it. Instead is three things lining up together. First, the warning. Low AdBlue triggers a message from the car, and running out leads to limp mode — so a hurried top-up, perhaps before work off Lower Luton Road, perhaps at The Malta on the way home after work. Then the car is unfamiliar. A hire car, a new motor or a company car puts the fillers where your last one didn't, and your hand hits for the cap it would have used on the old one. A spout-topped bottle finds no obstacle at a diesel filler any more than at an AdBlue one. So the pour, once begun, carries on. Bower Heath or the heart of Batford: it is the same few seconds either way. ## The AdBlue filler and the diesel filler: telling them apart Check these first, at a forecourt around Batford or a drive over in Marshalls Heath. Seconds, that's all. - Colour and marking: an AdBlue cap is commonly blue, or says "AdBlue", where a diesel cap usually doesn't. Go by the cap, not where it sits. - The size. On plenty of cars the AdBlue filler neck is the smaller of the two. - A label inside the fuel flap often says which fuel goes where, on many motors. Look for it. - In the boot or under the bonnet: that is where your filler sits if it is not by your diesel cap, and the handbook tells you which. - Ask the person who drove it last — before you leave, not when the light comes on — when you collect a hire or company car from somewhere like the car park outside Harpenden. ## Keeping AdBlue out of your diesel tank when you top up Anywhere around Hertfordshire the light comes on, here is a routine for the day. - Stop somewhere level, motor off, with time in hand — not hurried on the side of Station Road. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it works. - The diesel cap remains on. When the two sit under a flap, confirm it's closed before the bottle comes up. - Using the bottle's own spout, pour slowly — and stop when it's full or the bottle is empty. - Before starting your car, close the cap and look a second time that the diesel cap never opened off. Stop there if you find, at step two or three, that you've already poured into the diesel side. Step five stays out. ## Put AdBlue in the diesel tank around Batford already? The short order of things, starting with not starting your engine. The fuel pump starts on plenty of diesels the moment the ignition is switched on — and so leave it off. AdBlue doesn't mix with diesel — it sinks to the bottom of your tank, where your fuel is sucked from — so do not top up with diesel to thin it. If you're on a forecourt, whether it is the Esso or the BP, ask the attendants to help push the car away from the pump. Leave it where it is if you're on your own drive around Batford. If your motor has already run, stop as soon as it is safe and switch off. Leave the M1 — under 5 miles out of Batford — at the next exit. Roughly how far did it go? Hopping across Batford is less a job than a run of under 10 miles towards St Albans, so tell us. ## Our arrival around Batford, and what happens next Anywhere the car has stopped, whether outside Sauncey Wood Primary School, beside Batford Methodist Church or at home, the van travels to it. What liquid went in, the quantity, and if it ran: our technicians ask since the answers set the work and price. Nobody sets off until you have heard the quote over the phone. Then the tank is emptied and your system purged thoroughly. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own — which is why that matters more with AdBlue than with petrol. Filter cleaned or, if it must be, replaced; clean diesel in; and then a test of the vehicle. After that our technicians start the car and check it runs properly before we go. Using pumps safe on a busy forecourt and quiet enough to use outside a house at night, most jobs in which your motor hasn't run take about half an hour once our engineers are there. The insurer will ask for the engineer's report and your VAT invoice, and both are yours once the job is done. Payment comes on the day, with no deposit. Many insurance policies include misfuelling cover, and so it's worth checking yours whilst we are on the way. ## About Batford and where it is Batford is a suburban area in Hertfordshire, situated on the riverside at an elevation of around 90 metres. Batford lies approximately 23.7 miles from London and is close to the city of St Albans, which is about 5 miles away. Batford is surrounded by other nearby places such as Bower Heath, Mackerye End, and Harpenden, and is characterised by its predominantly semi-detached housing stock. Batford has a population of around 4703 residents. ## AdBlue drains about Batford, and Hertfordshire beyond Mackerye End and Harpenden are among the places around Batford, a residential suburb, that the same teams cover, throughout AL postcodes. The van reaches you fastest with a postcode starting AL5 5. Your car does not need to move. Our engineers drain it where it is — a side street close to All Saints, a lay-by on the way to Sports Field, a drive. If you are near a border, or somewhere hard to explain like the back of Batford Springs Nature Reserve Centre, ring and ask rather than assuming. ## In short, for Batford motorists Read the cap before you tip. Petrol in Diesel drains it where it stands, anywhere in Hertfordshire, if AdBlue has gone in the diesel tank anyway — and so leave the vehicle off then call 0333 366 0103.