Turn off your home's water supply

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Your trusted, local same-day plumbers

Some of our recent work....

Leak before the stopcock.

New stopcock/Thames Water call out.

Reading customer – Home owner Neil

Neil (and his young family) noticed a leak on their incoming water mains pipework just above their internal stopcock in their kitchen.

They got in touch and our plumbers were with them within 30 minutes. Unfortunately the internal stopcock had seized and the street Thames Water stop tap had failed – which meant that the water could not be turned off preventing the leak from being fixed.

Thames Water were called out on an emergency to replace their stop tap which they did within three hours. This enabled our plumber to replace the home’s internal stop tap and repair the leak.

Pinhole leak on incoming mains.

New stopcock/Thames Water call out.

Goring customer – Home owner Claire.

Claire noticed a hissing sound coming from behind her home’s downstairs toilet where the mains water entered the property.

Opening up the boxing showed a pinhole leak on the incoming water mains, before the internal stopcock and inaccessible.

Thames Water were contacted and after looking through their records identified an old, defunct stop cock connected to the house that could be reinstated.

Works took place the same day enabling the mains water to be shut off and the pin-holed pipe to be replaced.

The quickest way to get in touch to discuss turning off your water supply is to WhatsApp, text or phone us on 07442966664.

You can also email plumbing@angusplumbing.co.uk or use the form – and well get back to you as soon as we can.

The AngusPLUMBING team

Turning off your water supply?

Turn the water off. How do you turn off your homes water? When and why would you need to do this?

Being able to turn off the mains water’s needed for planned maintenance and essential in when you’ve a sudden emergency.

Emergency situations

The most urgent reason to shut off the mains is to stop active flooding.

Burst pipes: Often caused by freezing temperatures in winter or high water pressure, a burst pipe can unleash hundreds of gallons of water per hour.
Major leaks: If a pipe behind a wall or under a floor begins to leak heavily, shutting the mains is the only way to prevent structural damage, mould growth, and electrical hazards.
Uncontrollable overflows: If a toilet or sink is overflowing and the local isolation valve is stuck or missing, the main stopcock must be used to stop the flow.
Natural disasters: During events like severe storms, shutting off the water can prevent internal flooding if external drains are blocked or damaged.

Planned maintenance and repairs

You must shut off the water supply to work safely on any part of the plumbing system that does not have its own isolation valve. This includes installing new taps, showers, or water heaters.

Appliance installation: Connecting a new dishwasher or washing machine often requires a temporary shut-off to prevent leaks during the hookup.
Upgrading your home’s water system: If you are renovating a bathroom or replacing old, corroded pipework, the mains must be isolated.

Extended absence (holidays etc.)

Turning off the water when you leave for more than 24 hours is a highly recommended safety precaution. If you do not do this and there is a subsequent burst pipe or problem with your home’s plumbing that causes water damage your insurer may not pay out as you have not mitigated their risk/exposure. Its good practice to check your policy each time it renews so that you are aware of your insurance company’s requirements.

Preventing “silent” disasters: A small leak that starts while you are away can go unnoticed for weeks, leading to catastrophic damage and high utility bills.
Winter protection: If you are away during cold months, shutting the water and draining the pipes prevents them from freezing and bursting in your absence.
Testing the valve: It is recommended to turn your main stopcock off and back on at least once a year to ensure it hasn’t seized up from mineral buildup, so it works if you need it in a real emergency.

How do you turn off the water?

To turn off the mains water to your house, you primarily use the inside stopcock (or stop valve). If this is inaccessible or faulty, you can use the external stop tap.

Using the inside stopcock (preferred)

This is the main valve inside your property that controls the flow of water into your internal plumbing system. Common locations include:

Under the kitchen sink (the most common spot).
In a utility room, garage, or cellar.
Under the stairs or in a hallway cupboard.
Behind a panel in a downstairs bathroom or near the boiler.

Turn off the stopcock

Turn the stopcock’s handle clockwise (righty-tighty) until you feel resistance. Do not force it if it is seized; use gentle pressure. You can apply a small amount of penetrating oil (like WD-40 penetrant not regular WD-40) if it is stiff. It may take a few minutes for the water already in the pipes to drain out after the valve is closed.

Using the external stop tap (secondary)

If you can’t find or operate the internal valve, you must use the external one, which is usually located near the boundary of your property.

Location: Look for a small metal or plastic cover on the pavement or driveway, often marked with a “W” or “Water”.

Turn off the stop tap

Lift the lid (you may need a screwdriver to pry it open).
The valve is often deep underground; you may need a stop tap key (available at most DIY stores) to reach it.
If it’s not deep underground, you may find a long blue or black plastic “key” connected to the water meter. If this is missing a size 10 hex/allen key can normally be used as an alternative.
Turn it clockwise until the water stops.

Warning. In many areas, the external stop tap belongs to the water utility company. It should only be used in an emergency, and be aware that in terraced houses or flats, it may turn off the supply for your neighbours as well.

Isolating specific fixtures

If you only need to stop water to a single tap, toilet, or appliance, look for isolation valves on the pipes directly connected to them.

Chrome/slotted valves: Use a flat-head screwdriver to turn the slot 90 degrees so it is perpendicular (across) the pipe.
Lever valves: Turn the blue or red handle 90 degrees so it is no longer parallel with the pipe.

Confirmation. After turning any valve off, open a cold-water tap on the lowest floor to verify that the flow eventually stops and to relieve remaining pressure in the system.

Other plumbing services....

Our local plumbers provide a range of expert plumbing services that’ll keep you and your family safe, save you money and your home running smoothly and as it should including:

Improving water pressure and flow (to see our work click here).
Leak detection (to see our work click here).

Water and waste pipe repair & maintenance (to see our work click here).

Unblocking waste systems (to see our work click here).

Dripping/running overflow pipe investigation (to see our work click here).
Turning off/isolating your homes water supply (to see our work click here).
Repairing and maintaining your home’s water tanks (to see our work click here).