--- title: Explained: AdBlue in a Diesel Tank Bovingdon canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/bovingdon-hertfordshire/ location: Bovingdon county: Hertfordshire latitude: 51.722290 longitude: -0.531280 service: AdBlue in a Diesel Tank updated: 2026-10-16 --- # Bovingdon: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? AdBlue already in your diesel tank? Then put this page aside for now, keep the ignition and engine off, and phone 0333 366 0103. In Bovingdon, finding it before the engine turns normally leaves a drain and a full flush on the spot. Here in advance? Then the rest covers why it happens and how to prevent it happening at all. ## AdBlue in a diesel motor: two tanks, two fillers Not one liquid but two: that's what many modern diesels near Bovingdon and Venus Hill run, with diesel feeding your engine. Kept in a tank of its own, AdBlue is sprayed into the exhaust gas and cleans it. Each tank comes with a filler of its own. Under one flap, side by side: that is the layout on many vehicles. On others, AdBlue's filler sits beneath the bonnet or in your boot instead. Diesel gets filled at each forecourt call-out, week in, week out. Much less often, the AdBlue side is topped up — normally from a bottle, by someone thinking about where it goes. It's in that gap that the error happens. ## How does AdBlue in the diesel tank happen around Bovingdon? Carelessness rarely explains it. Instead is three things lining up together. On a driveway off Church Lane before work, or in the car park at The Bell Inn on the way home: that is where the hurried top-up takes place. Why the rush? As AdBlue gets low the vehicle tells you, and if it is gone, limp mode follows. The old car's filler is where the hand goes — yet a rental car, a new car or a company car keeps the fillers somewhere else. That is a second factor: a strange motor. And the bottle fits. A bottle with a spout goes into a diesel filler as easily as an AdBlue one, and so nothing stops the pour after it has started. It takes seconds, whether out in Bulstrode or right in the heart of Bovingdon. ## How to tell the AdBlue filler from the diesel one Check these before pouring, on a forecourt in Bovingdon or a drive over in Bourne End. Seconds, no more. - The cap. The AdBlue cap is regularly blue, or marked "AdBlue". The diesel cap usually isn't. Read it instead of going by where it sits. - Check the size: the smaller neck is, on many motors, the AdBlue one. - Look inside your fuel flap: many cars carry a label there saying which fuel goes where. - In the boot or under the bonnet: that's where your filler sits if it is not by the diesel cap, and the handbook says which. - Whoever had it before knows. Ask as you pick up a rental or company car — from Hemel Hempstead's car park, say — rather than once the warning comes on. ## AdBlue top-ups that never reach your diesel tank When the light comes on, wherever around Hertfordshire, follow this routine. - Stop somewhere level, motor off, with time to spare — not hurried on the side of High Street. - Say "AdBlue" out loud as you unscrew the cap, after you find the AdBlue filler and read it. Silly, yes, yet it does the trick. - If both sit under one flap, check your diesel cap is still closed before you lift the bottle — then leave it on. - Slowly does it, through the bottle's own spout, until it's full or the bottle is empty. - Before starting the vehicle, shut the cap and check a second time that the diesel cap was never came off. Spot at step two or three that it has already gone into the diesel side? Then stop just there. Leave out stage five entirely. ## Already put AdBlue in the diesel tank in Bovingdon? Short order, then. First: the engine remains off. Keep the ignition off as well, because on many diesels switching it on by itself runs the pump. Topping up with diesel will not dilute it: rather than mixing, AdBlue drops to the bottom of the tank, just where the fuel is drawn from. At a forecourt — Shell, Gulf or another — the staff will usually help roll the vehicle clear, if you ask. If you are on your own drive in Bovingdon, leave the car where it stands. Stop as soon as it is safe and switch off, if your motor has already run. Bovingdon sits under 5 miles from the M25; on it, take the first exit. Tell us roughly how far it went: a run towards St Albans, under 10 miles away, is a bigger job than a short hop across Bovingdon. ## Our arrival around Bovingdon, and what takes place next By Bovingdon Primary Academy, close to 3rd Air Division, US Air Force or on your own drive: wherever the car has stopped, our technicians come to it. What liquid went in, the amount, and if it ran: our technicians ask since those replies decide both work and quote. The price comes over the phone, ahead of any van leaving. The fuel system is then rinsed thoroughly, once the tank is cleared. With AdBlue that matters more than with petrol: it crystallises and is corrosive to some of the metals in a fuel system, and so it does not wash out on its own. The filter cleaned or, if needed, replaced; clean diesel in; and then a test of the vehicle. Your engine is fired up next and checked to confirm it runs smoothly, all before our technicians go. Unrun vehicles usually need a half-hour visit from the moment we arrive. The kit is fine on a live forecourt, and quiet enough for a driveway after dark. No money in advance; you settle up on the day. Afterwards, the VAT invoice and the report from the engineer go to you for the insurer. Plenty of insurance policies include misfuelling cover, and so it is worth checking yours while we're on the way. ## About Bovingdon and where it is Bovingdon is a village in Hertfordshire, situated inland at an elevation of around 153 metres, approximately 22.8 miles from London. Bovingdon lies near the cities of St Albans and Hemel Hempstead, with nearby places including Bulstrode, Whelpley Hill, and Westbrook Hay. Bovingdon has a population of around 2268 people, predominantly living in semi-detached housing. Bovingdon remains a residential community with a rural character. ## AdBlue drains about Bovingdon, and Hertfordshire beyond Over HP postcodes, our vans that cover Bovingdon — a rural village — work the surrounding locations too, Westbrook Hay and Whelpley Hill among them. Quote a postcode that starts HP3 0, and the van arrives quickest. Your car stays put. A driveway, a lay-by on the way to Bovingdon Bowls Club, a side street near Memorial Hall: our technicians drain it where it stands. Guessing won't help behind Ryder Memorial, close to a boundary, or somewhere awkward to describe; phone and ask. ## Bovingdon drivers: the short version Read the cap before you pour. Still AdBlue in your diesel tank? Petrol in Diesel will drain it where it is, anywhere in Hertfordshire: switch the vehicle off and phone 0333 366 0103.