How to fix a running toilet

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A constantly running toilet isn't just a pain in the neck – it can also become a huge waste of water, and that could mean you'll rack up a huge bill to match. Luckily, it's easy to fix a running toilet, and our step-by-step guide will show you everything you need to know.

1. Get prepared before you start

Depending on the type of float valve fitting you have in your toilet, you might need a few different tools. To be on the safe side, make sure you've got:

  • protective gloves and glasses
  • a pair of pliers
  • an open-ended spanner
  • both types of screwdriver

2. Check your overflow pipe

You can find your overflow pipe on the outside of your house, or you'll find it running down the inside of your toilet pan. If there's water continuously flowing out of it, it's a sign that you've got a problem with your float valve.

3. Take the lid off the back of your toilet

Before you can fix a running toilet, you'll need to get at the float valve inside the toilet cistern. Just pop the lid off the back of your toilet and place it somewhere safe.

4. Find the overflow pipe

You can check the level of the water by measuring it against the overflow pipe, which is usually found on the opposite side of the cistern to the float valve.

5. Measure the water level

Ideally, the water in the cistern should sit about 25mm (around 1 inch) below the top of the overflow pipe. If it's not sitting at the right level, you'll need to adjust the screw on the float valve.

6. Open the locking nut

Using your spanner, loosen the locking nut on the screw that's closest to the valve.

7. Adjust the float valve

Once the locking nut's been loosened, you can then turn the screw that's closest to the valve to adjust the water level. Turn the screw towards the valve to lower the water level, or turn it away from the valve to raise the water level. By following these simple steps, you should now know how to fix a running toilet yourself. But if you're still unsure, or you're still having trouble with your toilet, it might be time to call in one of our engineers to have a look.