How to Turn the Water Off?

Knowing how to safely turn off your water supply can save you a lot of time and money in an emergency situation, but sometimes it is not enough to simply turn off the stopcock valve in every situation. Understanding where the fault in your system lies is paramount to minimising water damage and the down-time of your system.

If you’re experiencing an emergency with water gushing everywhere then this could be highly stressful, as the longer you leave it the more damage is being done.

We have put this “how to turn the water off” article together for your information. Once you have read it we recommend you become familiar with the plumbing set up in your home. You can read our how to guide below.

If you need a general plumber or gas engineer, then do not hesitate in contacting us. We are based in Bourne End, High Wycombe and we cover all of west London including Marlow, High Wycombe, Acton, Wooburn Green, Henley, Hemel Hempstead, Hillingdon, Maidenhead, Windsor, Amersham, Reading, Beaconsfield, Gerrard’s Cross, Watford, and Redhill.

How to guide


Isolating Water to Appliances

Your home may have isolation valves fitted. This means you can turn off the water supply without having to shut off other outlets. Isolating valves are either lever or screw head operated and are positioned on pipes leading up to the appliance such as a washing machine or dishwasher.

Mains Water Supply (Direct Feed)

The mains water supply into the house can be turned off at the main stop cock or stop valve which is normally located under or near the kitchen sink. This will stop the mains water up to the stop cock. However if you have a cylinder for example, then remember you may also need to turn this off too (see below). If you can find the stop valve then you should be able to turn it off out in the street. It can be difficult to find however it is normally by the pavement in close proximity to your home. These are normally covered and have a mark. We advise you check with the water board first because you may unknowingly turn off the neighbours water and you may also require a special key.

Water Supply (Indirect Feed)

Many people turn off the mains but forget to isolate other water supplies which are fed indirectly. Water stored in a cylinder or cistern in the loft for example would supply water to the bathroom and other parts of the home. To turn this off you’ll need to turn off the valve on the cylinder or cisterns outlet supply.

Hot Water Supply

There are many different types of boilers such as combi, regular or system, so you will need to know whether it is direct feed or indirect feed. If you have a combi boiler then the hot water is supplied direct, so by closing the mains stop valve it will shut off the water. However, if you have a hot water cylinder this will be an indirect supply and there will be a valve on the pipe from the cold water storage cistern to the hot water cylinder. You will need to find this and turn it off.

Central Heating Systems

When draining down your central heating system you will need to stop it refilling, and depending on what type of system you have, there are a number of ways of doing this.

On a vented system, the water level is kept topped up by the feed and expansion cistern so if you drain down this type then you will need to temporarily close off the supply. Either close off the valve on the incoming pipe to the cistern or tie up the float valve.

On a sealed system, the filling loop will supply new water and will remain closed unless the system needs topping up. Keep it closed and only turn back on when you need to refill the system.


In an emergency such as a major water leak knowing how to isolate the mains water could save your house from unnecessary water damage. Thanks to Surestop, the process has been made a whole lot easier as Surestop allows you to turn off the mains water supply with the flick of a switch.

If you’d like to have a Surestop Water Switch professionally installed by our qualified plumbers, click the button below or call us on 01628 533 550 to contact our customer care team for a free quote.

DIY Plumbing Tips – How to turn the water off


Check out our plumbing and heating tips page. We maybe able to help you isolate the mains water, fix a leak or unblock a toilet, before having to call out an engineer. Also please read our gas safety article which has been written to help keep you safe.

Leaky pipe

Tips and Advice

Gas Safety Advice

Gas Safety Advice


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  1. Thanks so much for this. After reading this I went and checked where the isolation point were in my house. I now feel more confident that if anything does go wrong and the hubby is out, then I know what to do 🙂

  2. Well, maybe DIY isn’t quite for me when it comes to plumbing. I didn’t know there were that many things to have to find and turn off in case of an emergency. I really appreciate the post and I think I’ll leave this up to the professionals. Thanks for the post!

  3. Thanks for explaining about the hot water supply. We have some great local plumbing companies but I would like to start learning how to do more things myself so I don’t need to call a plumber for little things. We’ve been having some issues with our hot water so I would like to know what i’m looking at when I try to fix it. Who knows, I may just end up calling someone for help, but it’s worth a shot! Thanks again for the helpful instructions. I feel a little more comfortable about the situation now.

  4. I really like how you explain how to turn the water off in case of an emergency repair. People always forget that turning off your water is the first step when repairing any kind of plumbing. The other day I was trying to work on some backed up drain, but I was just not able to make it work. At what point should I call in the experts?

  5. Great post! This is such a helpful breakdown of plumbing basics and functions, especially in highlighting that turning the water off is the first step to preventing further damage. Thanks for sharing!

  6. There is a pipe in our basement that seem stop be leaking How can I get in front of this before it becomes a huge problem? If turn of the water, we cant shower, cook, etc. We also work, so it leaks during the day and I am afraid to come home to a flooded basement!

  7. Thanks for the advice Heppelthwaite the Red Van Plumbers. My wife read this article some time ago when you posted on Facebook. Last week we had a burst pipe and my wife turned the water off immediately. We had minimal damage that to simply knowing how to switch the water off. We would have called out the Red Van Plumbers but we don’t live in the area anymore.

  8. If there is demand on the 2 port valve but no output then likely the 2 port
    valve is faulty annd requires to get replaced. If you have any
    specific rules about smoking around the premises or hours oof work, ensure
    it’swell documented. Try to avoid this by not dropping pieces of soap into the draion – Mosst experts have claimed if you
    pour boiling water too the drain of one’s bathtub
    onnce every fohr weeks, it helps in stopping any clogs from occurring.

  9. This actually answered my problem, thanks!

  10. Keep up the great work! Thank you so much for sharing a great posts.

  11. Good write-up

  12. Wow! Amazing plumbing tips on some ways to turn off the water, Learned a lot! Thank you for sharing!

  13. Good products. Thanks for sharing this with us.

  14. The article has my interest. I am going to bookmark your website and keep checking for new information.

  15. Thank you

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