Listen and observe
Note whether water is visibly running into the bowl, whether the cistern keeps refilling, or whether the noise stops when the isolation valve is closed. This helps distinguish a supply-side problem from a flush-valve or seal issue.
Do not ignore a small continuous leak
A running toilet can waste substantial water over time. The repair should identify the failed component rather than relying on repeated adjustment of worn parts.
Photograph the cistern type
A clear photograph of the toilet and, where safely accessible, the internal cistern arrangement can help identify likely replacement parts before attendance.
Related information
Damp Wall Near Plumbing
Dampness near pipe routes can result from a concealed leak, waste leak, waterproofing failure, condensation or moisture from another source.
Dripping Tap
The correct repair depends on whether the fitting uses a washer, ceramic cartridge, mixer cartridge or another internal control.
Flexible Plumbing Hoses: Failure Signs and Prevention
Flexible connectors are small components with the potential to release a large amount of water if they split or detach.
How to Find and Use Your Main Water Shut-Off
Knowing how to stop the water can reduce damage while you wait for a repair team.