What to Do in a Plumbing Emergency

Your internal stop tap (also called the stopcock) is the master shut-off for mains cold water. It's usually under the kitchen sink, in a downstairs cupboard, or in the utility room. Turn it clockwise until it stops. If you don't know where yours is, find it now — see our guide on how to turn off your water at the mains.

If the internal stop tap is seized (common on older properties) or doesn't fully stop the flow, your external stop tap is in the pavement or front garden inside a small marked cover (often labelled "W"). You'll need a long key or a long-handled screwdriver to turn it.

Switch off the boiler at its electrical isolator (usually a switched fused spur next to the boiler) and turn off the central heating at the programmer. This stops the boiler trying to heat water that's no longer there — running a boiler dry damages the heat exchanger badly.

On a system or regular boiler with a hot-water cylinder, also turn off the immersion heater if it's likely to be running on a leak that's draining the cylinder.

With the mains off, open every cold tap in the house — kitchen, bathroom basins, bath, outside taps. This drains the pipework and stops residual pressure pushing water out of the leak. Do the lowest taps first (downstairs) and work up.

Don't open hot taps unless the boiler is fully off — running a hot tap with the cold supply cut can pull air into the system and damage the boiler.

While waiting for the engineer:

• If water is anywhere near electrical sockets, lights or your consumer unit, turn off the electricity at the consumer unit and don't touch any switches that have got wet
• Move valuables and electronics away from the affected area
• Lift carpets and rugs if water has reached the floor — drying them later is cheaper than replacing them
• Catch active drips in buckets and clear standing water with towels
• Photograph the damage — any insurance claim will need this
• Don't attempt DIY repairs on the leaking pipe — push-fit fittings or repair clamps applied wrongly often make leaks worse

When you call, have the following ready: your postcode, the type of emergency (burst pipe, major leak, no water, blocked drain causing back-up), whether you've successfully isolated the water, and whether anyone in the property is vulnerable.

Reactive answers the phone 24/7 — directly, no answering service. Average response across our daily-run area is around 90 minutes for genuine emergencies. See our 24/7 emergency plumbing service for what's included and our standard call-out approach.