What to do if…
water is running from an outside pipe and will not stop

What to do now

1. Keep people away and make a quick hot-or-cold check from a safe distance.

   • If there is steam, the pipe is too hot to approach, the water looks forceful, or the pipe seems linked to a boiler or hot water cylinder, treat it as a hot or safety discharge.
   • Do not touch the water stream. If it is safe, you can place a bucket where it will not tip, splash back, or send water toward the building.

2. If it may be hot or heat-related, switch off heat sources first.

   • Switch off the boiler at its power switch or fused spur.
   • Turn heating and hot water off at the programmer if there is one.
   • If you have an immersion heater, switch it off at its fused spur.

3. Turn off the internal stop tap to slow or stop the supply.

   • The internal stop tap is often under the kitchen sink, in a kitchen cupboard, utility room, downstairs toilet, cellar, garage, or where the mains pipe enters the home.
   • Turn it clockwise slowly until it stops; do not force it if it is seized.
   • If you are sure the problem is only a toilet cistern that keeps refilling, you can instead turn off the small isolation valve on the toilet supply pipe and leave the rest of the home supplied.

4. Look inside only for obvious clues, without taking things apart.

   • Check toilets for constant filling, trickling into the pan, or refilling after the cistern should be full.
   • Check whether a loft tank, if safely visible, is overflowing or noisy.
   • If you have a hot water cylinder cupboard, look for a tundish, which is a small visible gap in a discharge pipe, and note whether it is dripping or running.
   • Take a photo or short video of the outside pipe, the flow, and any obvious indoor clue for the plumber or engineer.

5. If you are in a flat, terrace, or managed building, reduce knock-on harm.

   • Tell any neighbour who might be affected by water on a shared wall, stack, balcony, path, or garden.
   • Contact building management, the freeholder, concierge, or managing agent if there may be a shared supply, shared pipe, or communal stop valve.

6. Get the right urgent help.

   • If you rent, report it to your landlord or letting agent’s emergency repairs contact and say what you have already turned off.
   • If it is linked to a gas boiler or gas heating, use a Gas Safe registered engineer and check they are qualified for the appliance and work.
   • If it may be an unvented hot water cylinder, often with a tundish, ask for someone qualified or competent for unvented hot water systems and Part G/G3 work.
   • If you cannot turn the water off, or the problem may be at the incoming supply or an external stop tap, contact your water company for urgent advice.

7. Limit damage while you wait.

   • Move valuables, electrical items, and absorbent belongings away from damp areas.
   • Use towels only for indoor drips where it is safe to do so.
   • Keep the discharge route outside clear so water does not pool against the building.