Leaking boiler? Stop the damage first, then call
A leaking boiler can wreck ceilings, floors and the boiler itself. Isolate first, then call — most leaks are one of five things and most are repairable.
You're not getting a call centre — you're getting Grant.
The same engineer quotes the job, does the work, and answers the phone afterwards if anything's not right.
Gas Safe Registered
Every gas job legally signed off
18+ years on the tools
Grant has been fixing boilers in Harlow since before smart thermostats existed.
Real human on the phone
Most calls answered the same day, often within the hour.
Locally based in your area
Not a national chain — your local engineer, your local prices.
The likely causes, in order
- PRV (pressure relief valve) discharge — Water dripping from a copper pipe outside points to a stuck-open PRV or over-pressurised system. Fix is usually expansion vessel service or PRV replacement.
- Pump seal failure — Weeping under the boiler at the pump — a replacement pump or seal cartridge is a common repair on 6+ year old units.
- Heat exchanger crack — The most serious cause and the one that usually ends a boiler's life. Confirmed with borescope inspection and pressure testing.
- Auto air vent failure — Small brass valve on top of the pump — cheap part, common leak point.
What you can safely try first
- Turn off the boiler at the front panel and at the electrical isolator
- Turn off the water supply into the boiler at the filling loop and any isolation valves
- Put a bucket or towels under the leak — take photos for insurance
Request a help · urgent quote in your area
Real engineer reply — usually within the hour during working times. Fixed written quote, no commission-driven sales, 12-month workmanship guarantee.
- Gas Safe registered
- Same-day cover where possible
- Fixed written quotes
- Manufacturer warranties up to 12 yrs
Frequently asked questions
Do I need a plumber or a boiler engineer?▾
A Gas Safe engineer for anything inside the boiler casing. A plumber for pipework outside the boiler is fine — we do both, saves you calling two people.
Will home insurance cover the damage?▾
Most policies cover the resulting water damage (ceilings, flooring) but not the boiler itself. Take photos before we start work.
Related pages you might want
Still stuck? Get a real engineer on it
Call us if the DIY steps don't clear it — same-day response where possible, fixed price before any tools come out.