Plumbing isolation valves
Plumbing isolation valves are quite simply some of the most useful devices that a DIY enthusiast can find in their home. These small valves allow you to turn off the water supply in one area of the plumbing system, so that you don’t have to drain down the whole system in order to carry out some work on a plumbing fixture or fitting.
What do plumbing isolation valves look like?
Isolation valves may have little taps on them, often colour coded in red or blue, but the most commonly used in the UK, are those pictured to the right. The way the valve is turned off or on is by using a slot head screwdriver to turn the screw in the centre of the valve (only a quarter turn is required).
If the slot of the screw is aligned with the pipe, then the valve is on and so water will be flowing through it. If the slot is running across the pipe (as shown in the photo), then the valve is in the off position.
Where do you find isolation valves?
You can find isolation valves pretty much anywhere in your plumbing system, but most commonly close to the taps in your kitchen and bathroom, near your washing machine or dishwasher, and just below your toilet cistern. Basically have a look at the supply pipes below any of these fixtures, and see if your pipework has had them fitted.
Generally, you’ll always find plenty of isolation valves in newer homes but in older properties they will only have been fitted if your plumbing system has been updated. This is one of the problems of DIY plumbing in older homes – no isolation valves means draining down large sections of the plumbing system, which is really only an option for more advanced DIY plumbers (a subject for a future plumbing guide).
Fixing taps and toilets
The greatest DIY use for isolation valves is when it comes to fixing plumbing fixtures and fittings such as taps and toilets. For taps, all you need do is turn the valves to the off position, open the taps to release the small amount of water that will be between the valve and the tap itself, after which, you are free to disassemble the tap, change a washer, or carry out repairs – simple. Once the work is done, just turn the valve back on.
Similarly, for a toilet, you simply turn the valve off, and you are free to empty the toilet cistern, carry out any maintenance such as fitting a new flush valve, or even remove the cistern completely if required.
Replacing kitchen and bathroom fittings
Of course, being able to shut off the water so close to a kitchen or bathroom fitting also means that not only can you fix a problem quickly, but you can also replace the fitting entirely. For much more information on how to replace, baths, basins, sinks and toilets, please have a browse through my Kitchen and Bathroom guides.
Therefore plumbing isolation valves are indeed a gift from the heavens as far as DIY is concerned; BUT, always give your plumbing system plenty of respect, don’t try anything you’re not sure of, and be aware that like any plumbing fitting, isolation valves can fail. However, in the vast majority of cases, isolation valves make plumbing much, much easier – I just love them!