In This Guide
Where is my internal stopcock?
The internal stopcock is the main valve that shuts off the cold water to your whole house. In most UK homes it is under the kitchen sink, but it is also commonly found in a utility room, downstairs cloakroom, under the stairs, in an airing cupboard, or near where the water pipe first enters the property. It looks like a tap or a lever on the pipe.
It is worth finding yours now, before you ever need it in a hurry. A stopcock you have located and turned in daylight is far easier to deal with than one you are hunting for while water is coming through the ceiling.
For expert assistance with water leaks or any plumbing concerns, contact 0800 Homefix. We’re just a phone call away and ready to provide professional solutions tailored to your needs. Don’t wait—reach out to us today. Your home’s plumbing is in safe hands with us.
How to turn off the water supply
- Locate the internal stopcock, most often under the kitchen sink.
- Turn it clockwise (to the right) until it will not turn any further.
- Open a cold tap, usually the kitchen tap, and let it run.
- When the flow slows to a stop, the water is off and you can work safely.
Turning off the cold supply this way stops water reaching the whole house. Your hot water cylinder, if you have one, may still hold water, which is normal.
What if the stopcock is stuck or will not turn?
Stopcocks that have not been touched in years often seize. Do not force a stuck stopcock, because you can snap it or turn a small problem into a burst. If it will not move, or it weeps after you turn it, leave it and use the external stop tap instead, then have the internal stopcock freed or replaced by a plumber. A stopcock you cannot turn is worth fixing before an emergency, not during one.
The external stop tap
Every property also has an external stop tap, usually just outside the boundary under a small round or rectangular cover in the pavement or driveway, near the water meter. It normally sits deeper than arm’s reach and needs a stop tap key to operate. Turning it clockwise shuts off the supply to your property from the mains. This tap is on the water company’s side, so it is intended mainly for use by a plumber or the supplier, but in a genuine emergency it is the backup when the internal stopcock will not work.
Isolating a single fitting instead
If you only need to work on one thing, you may not need to shut off the whole house. Many toilets, taps, and appliances have their own isolation valve on the supply pipe nearby, and radiators have valves at each end. Our guide to turning off the water to a toilet shows how to isolate a single fitting so the rest of your water stays on. If you are shutting off because you suspect a leak, our guide to checking for a water leak at home helps you confirm and locate it.
When to call a plumber
If you only need to work on one thing, you may not need to shut off the whole house. Many toilets, taps, and appliances have their own isolation valve on the supply pipe nearby, and radiators have valves at each end. Our guide to turning off the water to a toilet shows how to isolate a single fitting so the rest of your water stays on. If you are shutting off because you suspect a leak, our guide to checking for a water leak at home helps you confirm and locate it.
How 0800 Homefix can help
Most people can shut off their own supply once they know where the stopcock is. When the stopcock is seized, leaking, or missing, 0800 Homefix covers London and the South East and can free or replace it, fit isolation valves, and deal with the burst or leak that made you shut off in the first place. Knowing 0800 Homefix can attend quickly takes the pressure off in an emergency.
0800 Homefix charges as the first hour of labour, paid in advance, with any parts or further work quoted and agreed with you before it begins. For current rates, see our rates page. Our labour is guaranteed for 12 months, and any parts we fit are covered by the manufacturer’s 12-month guarantee.
Frequently Asked Questions
Where is the stopcock in my house?
Usually under the kitchen sink, but also in a utility room, downstairs toilet, under the stairs, an airing cupboard, or where the water pipe enters the property. It looks like a tap or lever on the pipe.
Which way do I turn the stopcock to turn the water off?
Clockwise, to the right, until it will not turn any further. Then open a cold tap to confirm the flow has stopped.
What do I do if my stopcock will not turn?
Do not force it. Use the external stop tap near your boundary instead, then have a plumber free or replace the internal stopcock before you next need it.
How do I turn the water off in an emergency?
Go straight to the internal stopcock and turn it clockwise. If it will not move, use the external stop tap by the boundary, which needs a stop tap key. Shut off first, then call a plumber.
Will turning off the stopcock stop my heating?
It stops the cold water supply to the house. A sealed heating system holds its own water, so shutting the stopcock does not immediately affect your heating, though you should not refill or top up the system with the supply off.
Helpful resources
- Consumer Council for Water: independent guidance on stop taps and water supply responsibility.
- WaterSafe: find an approved plumber to free or replace a stopcock.
Spotted Any of These Warning Signs?
Stopcock stuck, or dealing with a burst? 0800 Homefix has plumbers across London and the South East who can shut off, repair, and get your water back safely, seven days a week, 365 days a year.
Editorial note: This article is intended as a general homeowner guide. All plumbing work on supply pipes should be carried out by a qualified, WaterSafe-registered plumber. If you suspect a gas leak, leave the property immediately and call the National Gas Emergency Service on 0800 111 999.
