Where Is My Stopcock? How to Find Your Stop Tap
Reviewed by the Devon Leak Detection team. Last updated June 2026
The short answer. Your internal stopcock is most often under the kitchen sink, though it can also sit in an airing cupboard, garage, utility room or under the stairs. There may also be an external stop tap near your boundary, under a small cover in the path or verge. Knowing where yours is lets you turn the water off fast if a pipe bursts.
If a pipe lets go behind a kitchen unit or under the floor, the single most useful thing you can do is shut off the water at the mains. That is the job of your stopcock, sometimes called a stop tap. The trouble is that a great many people in Devon have never had to find theirs, and a flooding kitchen is a poor moment to start hunting. This guide walks you through the usual hiding places, explains the difference between the inside and outside taps, and shows you how to test yours before you ever need it in anger.
What a stopcock actually is
A stopcock is a valve fitted into your incoming water pipe. Turn it one way and the mains water flows into the house; turn it the other way and the flow stops. It looks a little like a tap with no spout, sitting in the middle of a run of pipe rather than at the end of it. Older homes tend to have a brass valve with a round wheel or a T-shaped handle that you turn clockwise to close. Newer fittings are often a quarter-turn lever: in line with the pipe means open, across the pipe means shut.
Most properties have two of them. There is an internal stopcock inside the house, which is the one you will reach for day to day, and there is usually an external stop tap near the boundary, which the water company can also use. Both sit on the same water line, so they tend to line up with each other across the front wall of the property.
Where the internal stopcock is usually found
The water enters most homes at the front, near ground level, so the internal stopcock is rarely far from the front of the property. By a wide margin, the most common spot is the cupboard under the kitchen sink, tucked behind the bottles of cleaning spray and the bin. That is the first place to look.
If it is not there, work through the other usual places. The fitting often turns up in a downstairs cloakroom or bathroom, in a utility room, in the garage, under the stairs, or in the hallway near the front door. In some homes, particularly flats and converted properties, it can be set into an airing cupboard or a service riser. The valve will always be on the pipe that carries cold water into the house, so following the rising main from where it comes through the floor or wall will lead you straight to it.
Places worth checking:
- The cupboard under the kitchen sink (the most likely spot)
- A downstairs toilet, cloakroom or bathroom
- The utility room, garage or under the stairs
- The hallway near the front door, where the main often enters
- An airing cupboard or service riser, common in flats
The external stop tap near your boundary
Outside the house, there is normally a second valve set into the ground near the edge of your property. It is usually hidden beneath a small cover in the footpath, the driveway, the garden or the grass verge, often roughly the size of a CD case. Lift the lid (a flat screwdriver helps with stiff ones) and you will typically see the valve, sometimes alongside your water meter, with a polystyrene cap that guards against frost.
This outside tap can be useful if you cannot reach the internal one, but bear two things in mind. It often sits down a narrow chamber that needs a long meter key rather than your hand, and the external stop tap usually belongs to the water company. In practice, the inside stopcock is the one to rely on for a quick shut-off, with the outside tap as a backup.
Who is responsible for which pipe
The boundary line matters because it usually decides who pays for repairs. As a general rule, the water company looks after the public main and the communication pipe up to your boundary, and you become responsible for the supply pipe from that point into the house. So a leak on the pipe running across your front garden is normally yours to sort out, while a problem out in the road is one for the water company. If you are unsure where your boundary falls or who maintains a particular stretch, it is worth checking with South West Water before assuming.
Test it before you ever need it
A stopcock you have never turned has a habit of seizing up. Valves that sit untouched for years can stiffen or stick, so it is well worth a gentle test on a calm afternoon rather than discovering the problem mid-emergency. Turn it slowly clockwise to close, run a cold tap to confirm the flow has stopped, then open it again. If it is very stiff, do not force it, and take care not to over-tighten when closing, as the washers inside can be brittle on older fittings.
While you are there, make a note of exactly where the stopcock lives and show anyone else in the household. If you have the plans for the property, the valve is sometimes marked SC. A minute spent now means that if a pipe ever bursts, you, or whoever is home, can stop the water in seconds instead of watching it spread.
When the water keeps going after you have turned it off
Shutting the stopcock cuts the mains, but water already sitting in the system will keep draining for a little while, so open the taps to let it run through. If water is still appearing well after the stopcock is closed, or if you can hear running water with every tap shut and the meter still ticking over, that points to a leak on the supply pipe somewhere between the valve and the fittings. That is exactly the kind of hidden leak we trace without tearing up floors. If you suspect one, our water leak detection service can pinpoint it, and you can find more practical guides on our articles page or read about the areas we cover across Devon.
Frequently Asked Questions
For a traditional wheel or T-shaped handle, turn it clockwise (the same way you tighten a screw) to close it. A modern quarter-turn lever shuts when it sits across the pipe rather than in line with it. Always turn slowly, and once it is closed, run a cold tap to check the flow has stopped.
A seized valve is common when it has not been touched for years. Do not force it, as you can snap the spindle or shear the pipe. Easing it gently back and forth sometimes helps. If it stays stuck, a plumber can free or replace it, and in the meantime you may be able to use your external stop tap as a backup.
The internal stopcock sits inside the house, usually under the kitchen sink, and is the one you use for a quick shut-off. The external stop tap is near your boundary under a cover in the ground and usually belongs to the water company. Both control the same supply, so they tend to line up across the front of the property.
As a general rule, the water company looks after the pipe up to your boundary and you are responsible for the supply pipe from there into the house. A leak in your garden is typically yours to deal with, while one out in the road is theirs. If you are unsure, check with South West Water before arranging any work.
Trace the rising main where cold water enters the house and follow the pipe; the valve is usually close to that point. Property plans sometimes mark it SC. If there genuinely is no accessible internal stopcock, you can use the external stop tap near the boundary, and it is worth having a plumber fit an internal one for convenience.
Water still appearing after the stopcock is off?
If you suspect a hidden leak on your supply pipe, our Devon team can trace it without disruption. Get in touch for a no-obligation chat.