--- title: Deganwy: AdBlue in a Diesel Tank, Explained canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/deganwy-conwy/ location: Deganwy county: Conwy latitude: 53.302820 longitude: -3.835130 service: AdBlue in a Diesel Tank updated: 2026-10-28 --- # Deganwy: How Does AdBlue End Up in a Diesel Tank, and How Do You Avoid It? Keep your engine and ignition off then phone 0333 366 0103 first — reading can wait if AdBlue is already in your diesel tank. In Deganwy, catching it before the engine runs normally means a drain and a full flush on the spot. If you're reading before it has happened, the rest of this page is about why it occurs and how to make sure it does not. ## AdBlue in a diesel car: two tanks, two fillers Many current diesels on the roads round Deganwy and Craig-y-Don carry two liquids, not one. Diesel goes to the motor. AdBlue's own tank keeps it, and from there it is sent to the exhaust, and there spraying cleans the fumes. Each tank comes with one filler of its own. On a lot of motors the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. Diesel gets filled on every filling station visit, week in, week out. A driver who has to stop and think where it goes normally fills the AdBlue side, from a bottle, and far less regularly. The mistake grows in that gap between them. ## How does AdBlue in the diesel tank happen around Deganwy? Three things tend to line up, and carelessness is seldom one of them. On a driveway off Ffordd Deganwy before work, or in the car park at West Shore Social Club heading home: that is where the hurried top-up happens. Why the rush? As AdBlue runs low your car tells you, and once it's gone, limp mode follows. Next, the hand reaches for the cap it knew on the old vehicle — since a rental car, a new motor or a company car puts the fillers where your last one did not. Lastly, the bottle fits: a diesel filler or AdBlue filler, it goes in as easily, and after the tip begins, no part stops it. Whether it occurs in Llanrhos or the middle of Deganwy, it's the same few seconds. ## Telling the AdBlue filler from the diesel filler Before you pour anything, whether on a driveway in Llandudno or a forecourt in Deganwy, check these. They take a couple of seconds. - Blue and lettering: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap usually doesn't. Trust the cap, not where it sits. - On plenty of motors, the size tells: AdBlue gets the smaller filler neck. - Open the flap and check for a label — many motors show which belongs in which filler just there. - Cannot see it next to your diesel inlet? In that case look beneath the bonnet or in the boot — the owner's manual will say which. - The person who drove the car last. On a hire or company car picked up from somewhere like the car park outside the nearest station, ask before you leave, not when the light comes on. ## How to top up without AdBlue in the diesel tank A routine for the day the light comes on, wherever around Conwy that is. - Park then switch off. Not on a slope, not with your motor running, and not in a rush on the side of Rockfield Drive. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds silly and it works. - Both behind a single flap? Then make sure the lid on the diesel side is still closed ahead of lifting the bottle. - Gently does it, through the bottle's own spout, until it is full or the bottle is empty. - Close the cap and check once more. Make sure your diesel cap was never opened. Only then start your car. Stop there if you find, at step two or three, that you've already poured into the diesel side. Skip stage five entirely. ## AdBlue in your diesel tank already, in Deganwy? Then the order of things is short. Don't start your engine. Do not switch the ignition on; on plenty of diesels that alone runs the fuel pump. Topping up with diesel won't dilute it: rather than mixing, AdBlue sinks to the bottom of the tank, right where the fuel is taken from. The attendants at Asda, JET or another forecourt will normally lend a hand pushing the vehicle away when asked. If you are on your own drive in Deganwy, leave the car where it stands. Already started? Pull over once it is sensible, then switch off. Leave the Moreton Spur — under 50 miles out of Deganwy — at the next exit. Tell us about how far it went: a run towards Bangor, under 15 miles away, is a bigger job than a short hop across Deganwy. ## Our arrival in Deganwy, and what happens next The van reaches your car anywhere it has come to rest — your own drive, near Bryniau Lookout Tower, or by the local primary school. What liquid was put in, the amount, and whether it ran: we ask since the replies set both work and price. On the phone call itself, you are told our price — ahead of dispatch. Then the tank is emptied and your system flushed thoroughly. AdBlue crystallises and is corrosive to some of the metals in a fuel system, and so it doesn't wash out on its own — which is why the flush matters more here than with petrol. The filter cleaned or, where needed, replaced; fresh diesel in; then a test of the car. Before we go, we fire it up and check that it is running smoothly. Unstarted cars usually need a half-hour visit from arrival. The equipment is fine on a busy forecourt, and hushed enough for a residential street after dark. You pay on the day, with nothing upfront, and get a VAT invoice and an engineer report for your insurer. It's worth checking your insurance as the van travels to you: misfuelling cover is included with plenty of policies. ## About Deganwy and where it is Deganwy is a coastal suburban area in Conwy, Wales, situated near the mouth of the River Conwy and overlooking the Irish Sea. Deganwy has a population of around 1373 people and is characterised by detached housing. Deganwy is close to nearby places such as Llanrhos and Cadnant Park, and is within commuting distance of Bangor. Deganwy sits at a relatively low elevation of 17 metres above sea level. ## Deganwy and Conwy: AdBlue drains across the area Tywyn and Cadnant Park are among the places near Deganwy, a residential suburb, that the same vans cover, throughout LL postcodes. A postcode starting LL31 9 gets our van to you fastest. Your car does not need to move. Wherever it sits — near Castell Degannwy, in a layby en route to Maesdu Golf Club, at home — that is where it is drained. Assuming doesn't help behind Peniel Elgwys Presbyteriadd Cymru, on a boundary, or somewhere hard to pin down; phone and ask. ## Deganwy people: the short version Before you pour, read the cap. Petrol in Diesel drains it where it stands, anywhere around Conwy, if AdBlue has gone in your diesel tank anyway — so leave the vehicle off and phone 0333 366 0103.