What to Do If Your Boiler Leaks

If you smell gas, hear a gas leak or suspect fumes, leave the property. Do not operate switches or use phones inside. Call the National Gas Emergency Service on 0800 111 999 from a safe place. Only re-enter when the network operator says it is safe.

If there is no gas smell and only water is dripping, switch the boiler off at the controls and isolate the electrical supply to the boiler if you can do so safely. Turn off the water feed to the boiler or the main stopcock if the leak is significant. Place a bowl or towels under the drip and keep people and pets away from hot surfaces and wet floors.

Do not keep resetting a boiler that is losing pressure, leaking from a heat exchanger or filling the condensate area with water — that can cause further damage. Note the boiler make, model and any fault codes on the display; this helps the engineer diagnose faster on arrival.

Emergency Plumber Chelsea sends Gas Safe registered engineers for boiler leaks across SW3, SW10 and surrounding Chelsea streets. We diagnose the source (PRV, pump seals, heat exchanger, pipe joints), make safe and quote for repair or replacement before major work.

Quick tips

• If you smell gas: out of the property, then National Gas Emergency 0800 111 999 — not a plumber first.
• Never block boiler vents or flue terminals; incomplete combustion is dangerous.
• Check system pressure on a combi (often 1–1.5 bar cold); sudden drops with a wet floor mean a leak, not just “top up and forget”.
• Keep annual service records; they help with warranty and insurance after a leak.

FAQs