This is one of those problems that looks small… until it isn’t.
A “little puddle” under the boiler can be a loose joint you catch early — or it can be a sign something inside has had enough.
Either way, the main aim is the same: stay safe, stop it getting worse, then fix the cause.
This page is written from callouts we do across East London and wider London. No scare stuff. No fluff.
If you’re near Stratford/Forest Gate and you’ve got water spreading on the floor, call 07727 154746 and we’ll tell you what to shut off first.
If there’s a steady drip or a puddle forming, don’t keep it running “to see if it stops”. Boilers don’t heal themselves — they just move water around more.
If water is anywhere near the boiler’s fused spur, nearby sockets, or underfloor electrics, switch off the circuit if you can. If you’re not confident, don’t guess — call and we’ll talk you through it.
Sounds basic, but photos help later (insurance, landlord, or even just remembering where it was leaking from). Put a towel down to stop it spreading under units/flooring.
Long CTA: If it’s leaking from underneath and you can’t tell where it’s coming from, call 07727 154746. We’ll ask a few quick questions and tell you if it’s shut-off-now urgent or a same-day repair job.
If you want this diagnosed and repaired properly (rather than guessing parts), see our main boiler repairs service in London for what we cover and how we handle callouts.
Boiler leaks often show up as damp patches elsewhere too. If you’re dealing with staining, swollen skirting, or “mystery damp” near the boiler cupboard, use our main hub here: damp and leak detection guidance in London.
We’ve been to jobs where the “boiler leak” turned out to be a pipe joint in the same cupboard, or a slow radiator valve drip that only showed once the heating kicked in. That’s why diagnosis matters more than parts-shopping.
If water is spreading fast or you’re not sure what’s leaking, start here: 24/7 plumbing callouts across London.
This is the “good news” scenario. It’s common after vibration, older installs, or a fitting that’s been nudged during other work. You’ll often see a drip line or a wet trail from one specific point.
Sometimes the boiler isn’t “leaking” so much as dumping pressure to stay safe. If pressure keeps climbing then dropping, that points to underlying causes (often expansion vessel related).
Condensate pipes, traps, and internal seals can cause drips that look like a mysterious leak. People notice it more in cold spells or after resets.
This is where you stop messing about with tape and bowls under the boiler. If it’s internal, it needs proper repair — and sometimes it’s the point where you discuss whether repair still makes sense.
If the boiler pressure drops but you don’t see water at the boiler every time, the leak might be elsewhere on the heating circuit. Look for damp around radiator valves, airing cupboards, and hidden pipe runs.
Not sure if this counts as urgent? This guide explains it clearly: is this a boiler emergency?
We don’t turn up and guess. We isolate, inspect, test, then explain what’s going on in normal language. If it’s a simple external leak, we fix it. If it’s internal, we’ll tell you the honest options — including when it’s smarter not to throw money at it.
One of the most common ones: someone wipes the water up, it stays dry for a day, then it leaks again only when heating kicks in. That pattern matters. We look for “only under pressure” behaviour — not just a wet patch after the fact.
If you want a straight answer, call 07727 154746. Tell us where the water is and whether pressure is dropping — we’ll advise the next step.
Boilers don’t do well with water where water shouldn’t be. Call 07727 154746 and we’ll help you decide what to do next — whether that’s a quick same-day fix or a proper diagnostic visit.
For service booking info, see our main boiler repairs page. If you’re worried it’s urgent, start with boiler emergencies (24/7).