To find the shut-off valve for water, look first under the kitchen sink, where the mains supply usually enters a UK home. The internal stop tap looks like a spout-less tap or lever between two pipes. Turn it clockwise to shut the water off. If it isn't there, check the downstairs toilet, utility room or under the stairs, or use the outside stop valve near your boundary.
When a pipe lets go or an appliance floods, the few minutes it takes to find the water shut-off valve can be the difference between a mopped-up puddle and a soaked ceiling. The trouble is that most of us never look for it until water is already running across the floor. This guide shows you exactly where the valve is in a typical UK home, what it looks like, and how to turn it off without making things worse, so you can find it now, before you need it.
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What the water shut-off valve actually is
Your home's water shut-off valve, usually called the stop tap or stopcock, is the control that isolates the mains water supply to your property. Turn it off and the flow to your taps, toilets, boiler and appliances stops. It's the first thing to reach for in a plumbing emergency, and the first thing a plumber will ask you to find.
Most UK homes actually have two shut-off points:
- An internal stop tap inside the house, which is the one you'll use in almost every situation.
- An external (outside) stop valve near your property boundary, usually owned by the water company and kept as a backup.
Knowing where both are, and which one to use, takes the panic out of a burst pipe.
Where the internal stop tap is (start here)
In most UK homes the inside stop tap sits under the kitchen sink, because that's typically where the cold mains supply enters the building. If you look at the back wall of the cupboard you'll usually see a pipe running down to a tap or lever. That's it.
If it isn't under the kitchen sink, it's likely to be somewhere else along that incoming supply. The places worth checking, in rough order of likelihood:
- Under the kitchen sink or in a nearby kitchen cupboard
- In the downstairs toilet or bathroom (sometimes behind the loo or a washing machine)
- A utility room or boiler cupboard
- Under the stairs or in the hallway
- The garage
- A cellar or basement, near where the pipe comes through the floor
In flats and newer builds it can be tucked inside an airing cupboard or a service riser. Older homes sometimes have it set low on a wall where the supply pipe rises from the floor. Affinity Water notes the inside stop tap is usually where the supply pipe enters the home, so follow the incoming pipe and you'll generally find the valve on it.
What an internal stop tap looks like
It looks like an outdoor tap without a spout, or a quarter-turn lever, fitted in line between two short lengths of pipe. Older versions have a round, crosshead handle you turn several times; modern ones often have a straight lever that moves through a quarter-turn. Either way, you're looking for a handle on the pipe rather than a fitting on the wall.
The outside stop valve and water meter
The external stop valve is your second shut-off point. It's normally found near your boundary, under a small cover on the path, driveway or pavement, often about the size of a CD case. The cover is metal or black plastic and may be marked "WATER", "STOPCOCK" or simply "W". Lift it and you'll see a valve down a short chamber.
If you have a water meter in an outside boundary box, there's frequently a stop valve right beside it that isolates your supply. To reach down into the chamber and turn it you may need a meter key or universal stopcock key, available cheaply from any DIY shop. It's a handy thing to keep under the sink.
On a shared supply, take care. If several homes share one supply pipe, turning off the outside stop valve can cut the water to your neighbours too. Let them know before you shut it off, and use your internal stop tap for routine jobs wherever possible.
Treat the outside valve as a backup. The water company generally owns it, and may ask you to seek permission before operating it except in a genuine emergency. For everyday tasks like sorting a leaking outdoor tap, swapping a dripping shower head or fixing a leak under the sink, the internal stop tap is the one to use.
How to turn the water off safely
Once you've found the valve, shutting off is straightforward. A little care saves a lot of grief, because old stop taps can seize and snap.
- Turn it clockwise. "Righty-tighty" closes the valve. On a lever type, turn it so the handle sits across (at right angles to) the pipe.
- Go slowly and don't force it. Turn gently. If it's stiff, easing it back and forth a little can help, but never wrench a seized handle, as a sheared stop tap turns a small problem into a flood.
- Wait a moment. It can take a few minutes for the water already in the pipes to drain through, so the flow won't always stop instantly.
- Check it worked. Run the cold kitchen tap, the one nearest the mains. When it slows to a trickle and stops, the supply is off.
It's well worth doing this as a dry run today, while everything is calm. A stop tap that hasn't been touched in years is exactly the one that sticks when you finally need it. To turn the supply back on, turn the valve slowly anti-clockwise, then run a tap to clear any air.
What to do if the valve is stuck
Seized stop taps are common, especially in older Cornish and Devon homes where the valve hasn't moved in decades. If yours won't budge:
- Don't apply brute force. Forcing a corroded brass stop tap can snap the spindle and leave you unable to stop the water at all.
- Try the outside stop valve instead to isolate the supply from the boundary while you sort the internal one.
- Consider fitting a modern lever service valve. A plumber can replace a tired stopcock with a quarter-turn valve so future shut-offs are quick and reliable.
If water is actively leaking and you simply can't isolate it, that's the moment to call for help fast. A leaking valve, or a stopcock you can't turn during an emergency, is one of the situations covered in our guide on whether a leaking stopcock is an emergency.
Who is responsible for which pipe
Knowing where your responsibility starts and ends helps when a leak appears near the boundary. In broad terms across England and Wales:
| Section of pipe | Usually responsible |
|---|---|
| The water main in the street | Your water company |
| The communication pipe (main up to your boundary) | Your water company |
| The outside stop valve at the boundary | Your water company (owns it) |
| The supply pipe from the boundary into your home | You, the property owner |
| The internal stop tap and all pipework inside | You, the property owner |
So if a leak sits on the supply pipe between your boundary and your house, it's generally your responsibility to put right. That's exactly the kind of buried, hard-to-see leak where professional water leak detection earns its keep, finding the leak without digging up the whole garden.
Frequently asked questions
Where is the water shut-off valve in a UK house?
The internal stop tap is most often under the kitchen sink, where the cold water enters the home. If it isn't there, check the downstairs toilet, utility room, under the stairs, the garage or a cellar. There may also be an outside stop valve near your boundary, under a cover in the ground.
Which way do I turn the valve to shut the water off?
Turn the valve clockwise to close it and stop the flow. Turn it slowly and never force it, as old stop taps can seize or shear. It may take a few minutes for the water already in the pipes to drain through before the flow stops completely.
What does a water stop tap look like?
An internal stop tap looks like a spout-less tap or a lever sitting between two short lengths of pipe. An external stop valve is usually a separate tap down a small chamber, reached under a metal or plastic cover in the ground near your property boundary.
Can I turn the water off at the meter?
If your meter is in an outside boundary box, there is often a stop valve beside it that turns off your supply. You may need a meter or universal stopcock key to reach and operate it. On a shared supply, the outside valve can also cut off your neighbours, so warn them first.
What if my stop tap is stuck or won't turn?
Don't force a seized stop tap, as it can snap and cause a much bigger leak. Try the outside stop valve instead, or have a plumber fit a lever-handle service valve so future shut-offs are easy. If you can't isolate the water and it's leaking, call a plumber or leak specialist quickly.
Who is responsible for the outside stop valve?
The external stop valve is generally owned by your water supplier, and they may ask you to seek permission before operating it. The supply pipe from the boundary into your home is normally your responsibility, while the company looks after the main and the communication pipe up to the boundary.
Found the valve but still losing water? Let's find the leak
If you've shut off the supply and a leak is still doing damage, or you can't trace where the water's coming from, we locate hidden leaks across Cornwall & Devon with non-invasive equipment, then give you the report your insurer needs. Fast response, minimal damage. See our plumbing leak detection service.
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