How to Replace a Cistern Valve in 6 Steps

Inside a toilet tank
  • 1-2 hours
  • Beginner
  • 0-50
What You'll Need
Replacement washer
Rubber gloves

Knowing how to replace a cistern valve can save you time and money because you will not need to hire a costly plumber. By following the required steps, you will find that preventing your toilet from running is a simple job.

Step 1 - Remove Cover

The first step is to remove the cover from the tank. You will need to access the cistern’s internal mechanism, including the cistern valve. If you have a cistern that has the flush button on top, you must unscrew this before you are able to lift the lid off. A standard cistern lid can simply be lifted out of place. Set it aside on a flat surface where so there is no danger of it tipping over or being stepped on.

Step 2 - Investigate

With the lid set aside, you will be able to see all the inner workings of the cistern, which should all be immersed in the freshwater that swirls through the bowl when the toilet is flushed. You may even be able to see the cause of the problem because there is a pipe in the middle of the tank that water should not be going into. Whether your toilet runs continuously, or only flushes intermittently, the problem is likely to lie with the cistern valve.

The valve is the point from which the tank refills after the toilet has been flushed and is usually located at the base of the cistern tank. Flush the toilet to get rid of the water in the tank and shut off the water supply. The shut off should be located either on the wall or the floor by the toilet.

Step 3 - Remove Cistern Valve

To take a closer look at the cistern valve and establish the defect, you must remove the cap that holds it in place. Though it depends on the type of cistern you are dealing with, you will probably simply be able to unscrew this by hand by pressing down firmly. Alternatively, use a screwdriver to undo the screws that hold the cap in place.

Step 4 - Examine Parts

tools on the tank of a toilet

Once it has been removed, you will be in a position to check the valve properly to determine where the defect lies. If it was tightened properly, it is likely to be due to a broken or worn washer which fits within the valve.

Gently remove the washer by prying it up at the edge, using a screwdriver before pressing a new one into place. Position the valve back into its original place and secure it by screwing it tightly.

Step 5 - Test

Leaving the lid off, let the tank refill with water before flushing the toilet. Watching the process will allow you to determine that it is working properly and where the defect lies if it fails to work. In the event that it works as it should, carefully replace the lid.