Your stopcock is the tap that turns off all the water coming into your home. When a pipe bursts, it's the single most important thing to find. Most people only look for it once water is already everywhere, so it's worth two minutes now.
What is a stopcock?
A stopcock (also called a stop tap or stop valve) is a small valve on the main water pipe where it enters your home. Turning it off stops water flowing to every tap, toilet and appliance in the house.
What does a stopcock look like?
It usually looks like a small tap without a spout, sitting on a copper or plastic pipe. Most have a round or T-shaped handle, often brass coloured or red. Some newer ones have a blue lever instead.
Where is my stopcock?
- Under the kitchen sink. By far the most common place. Look at the back of the cupboard.
- Near the front door, sometimes under a floorboard or in a cupboard
- In a downstairs toilet, utility room or under the stairs
- In a flat: often in a hallway or airing cupboard, or in a shared cupboard outside your front door. Your building manager will know.
Where is my external water stopcock?
Most homes also have an outside stopcock under a small metal or plastic cover in the pavement or front garden, near your boundary. It belongs to the water company, but you can use it in an emergency if it's safe. You may need a long stopcock key to reach it.
How to turn off your stopcock
- Turn it clockwise until it stops. Don't force it.
- Turn on your cold taps to drain the water left in the pipes.
- Turn off your boiler or immersion heater if you'll be without water for a while.
Check yours today
Turn your stopcock off and on once or twice a year so it doesn't seize up. If it's stiff, leaks, or doesn't stop the water completely, get it replaced before you need it in a hurry.
Common questions
Which way do I turn a stopcock to turn the water off?
Clockwise turns the water off. Anticlockwise turns it back on.
What does a stopcock look like?
Usually like a small tap with no spout, on a copper or plastic pipe. It has a round or T-shaped handle, often brass or red, or a blue lever on newer ones.
Where is the stopcock in a flat?
Often in a hallway, kitchen or airing cupboard, or in a shared cupboard outside the flat. Ask your building manager if you can't find it.
What if my stopcock won't turn?
Don't force it with tools, as old stopcocks can snap. Call a plumber, who can stop the water another way and replace the valve.