Most people don’t give much thought to their water supply until there’s a problem. However, knowing how to turn off your water supply can help prevent significant damage if you have a plumbing emergency, like a burst pipe or a leaky tap.
In this guide, we’ll show you how to turn off your main water supply and the water supply to individual fixtures. We’ll also discuss why you might need to turn off your water supply, explain the different types of water shut-off valves you’ll have, and advise when it’s best to call in a professional plumber.
This guide covers:
When would you need to turn off water supply?
Types of water shut-off valves
How to turn off the main water supply: Step-by-step
How to turn off water supply to individual fixtures
When to call in a JustFix professional
FAQs about turning off water supply
When would you need to turn off your water supply?
Several situations might require you to turn off the water supply, including emergencies and routine plumbing work. You may need to turn off your water supply for:
- Fixing leaks
- Preventing damage if a pipe bursts
- Installing new appliances like a dishwasher or sink
- Going on holiday to minimise the risk of damage
- Leaving a property or seasonal home unoccupied for a long time
Types of water shut-off valves
Knowing the types of valves, their function, and their location within your home is helpful if you need to turn off your water supply. Here are the main types of water shut-off valves found in UK homes:
Main stopcock
The main stopcock, also known as the internal stop tap, controls the water supply to your whole property.
It’s typically found under the kitchen sink, under the stairs, or in a ground-floor cupboard. If you have a shared water supply with neighbours, it could be located where the water supply enters the building.
Turning this valve off stops water flow to the entire house. This is the go-to valve to turn off if there’s a major leak or if you’re undertaking plumbing works.
External stopcock
The external stopcock is located outside your property boundary, usually in a small underground box known as a water meter box. It’s used to control the water supply from the mains.
If the internal stopcock isn’t working or is hard to find, you can use the external stopcock to shut off the water to your property. However, you’ll need a stopcock key to operate it. This valve may sometimes be shared with neighbouring properties.
Local isolation valves
Local isolation valves are small valves or levers found on the pipes leading to individual fixtures like sinks, toilets, or washing machines.
These valves are useful when you only need to shut off water to a single fixture. They’re often located under sinks, behind toilets, or near appliances.
Turning off an isolation valve won’t affect the water flow to the rest of your home.
How to turn off the main water supply: Step-by-step
If you need to turn off the water supply to your entire home, follow these steps:
1. Locate the main stopcock
Start by finding your main stopcock. In most UK homes, it’s under the kitchen sink, in a ground-floor cupboard, or under the stairs. Look for a lever or a wheel-shaped valve.
2. Turn off the stopcock
Once you’ve found the valve, turn it clockwise (to the right) until it’s fully closed. This will shut off the water flow to your entire house.
3. Check the water flow
To make sure the water is off, turn on a tap in your home. If no water comes out, the stopcock is closed. The water may take a few minutes to travel through the pipes and stop running, so be patient.
4. Use the external stopcock
If you can’t locate the main stopcock, or turning it off doesn’t work, locate the external stopcock. It’s usually outside, near the boundary of your property or on the pavement.
To turn it off, you’ll need to use a stopcock key, which can be purchased online or at hardware stores. Insert the stopcock key and turn it clockwise until the water stops.
How to turn off water supply to individual fixtures
If you only need to turn off the water to a specific fixture, such as a sink or toilet, you can use the isolation valves. This is useful when you need to keep the water supply flowing to the rest of your house during work or emergencies.
Here’s how to turn off the water supply to some common fixtures:
1. Sinks
Locate the isolation valve, which should be just under the sink. It’s usually a small lever or screw-head valve attached to the water pipe. Turn the valve clockwise until the tap stops running.
2. Toilets
The isolation valve for a toilet is usually located directly next to it, near the base or on a pipe attached to the toilet. Turn it clockwise to shut off the water supply. If it’s stiff or too small to grasp, you may need to use a flathead screwdriver.
3. Showers and baths
Isolation valves for showers and baths can also be located just below the fixture. However, they may be hidden behind access panels, in cupboards, or under floorboards in your bathroom. Once you’ve located the valve, turn it clockwise to stop the water flow.
4. Washing machines and dishwashers
Valves for appliances like washing machines and dishwashers are usually found on the wall behind the appliance or in a cupboard next to it. There may be separate valves for hot and cold water. If so, turn both valves clockwise to stop the water supply before moving or repairing the appliance.
When to call in a JustFix professional
If you can’t locate or turn the stopcock, booking a plumber to help may be necessary. What’s more, sometimes turning off the water supply isn’t enough to fix the issue at hand, or it might only provide temporary relief from the problem.
Here’s when it’s best to get help from an expert:
- If the stopcock or valve won’t turn: Forcing a stopcock or isolation value that won’t turn could lead to a broken valve and more severe leaks. Instead of applying too much pressure and risking this, enlist the help of a professional plumber.
- If you can’t locate the stopcock: If you can’t find your internal or external stopcock, it’s in a hard-to-reach place; a plumber can help you locate and access it. This may be necessary for older properties where stopcocks may be hidden behind panels or under flooring.
- If turning off the water supply doesn’t stop the problem: If turning off the valve doesn’t stop a leak completely, or if you notice water damage even after turning off the main stopcock, there could be a more complex issue. A professional plumber can figure out the problem and recommend the right solution.
- Major plumbing emergencies: Problems like burst pipes or flooding can cause severe damage to your property if they’re not dealt with promptly and properly. In these situations, it’s best to contact a plumber immediately instead of trying to solve the issue yourself.
With JustFix, it’s never been easier to find and book a local tradesperson. Simply tell us a few details about the job at hand, and we’ll match you up with a trusted plumber in your local area, quoting a fixed hourly rate for the work.
Best of all, with our emergency response service, you can book a verified plumber to arrive in as little as 30 minutes. Plus, our 12-month warranty on all work means you can relax knowing that whatever we fix stays fixed.
FAQs about turning off water supply
Where is the stopcock?
Your stopcock will usually be located under the kitchen sink, in an airing cupboard, or in a cupboard under the stairs. Other possible locations include under the stairs, under the floorboards, near the front door or in your garage, utility room, bathroom, or cellar.
What if I can’t reach a stopcock or valve?
If you’re struggling to reach your stopcock or valve to turn it off, it’s best to call a plumber. Plumbers have specialist tools and techniques that you might not benefit from.
What if I live in a flat and can’t access the main stopcock?
You might not have access to the main stopcock in some rental properties and shared accommodations like flats or apartments. In this case, it’s best to contact your landlord or maintenance provider to grant you access or resolve the problem themselves.
