Toilet keeps running after a flush?
Water that continues to run into the bowl or cistern after flushing can waste water and may indicate a flush valve or fill mechanism problem. The visible overflow and timing help narrow it down. Cistern designs vary, so do not dismantle an unfamiliar system.
Common clues
- Flush valve not sealing
A flush valve that does not return to its seat can let water pass continuously into the bowl. Debris or wear may be involved.
- Fill valve or float issue
A fill valve that does not stop at the correct level can send water toward the overflow. Do not adjust an unfamiliar float mechanism.
- Button or handle staying engaged
A stuck flush button, cable, or handle can hold the flush mechanism open. Check whether the control returns normally without forcing it.
Useful checks before calling
- 1Listen and locate the water
Note whether water runs into the bowl, flows through an overflow, or continues filling the cistern after the flush.
- 2Check the flush control
Make sure a button or handle returns to its normal position. Do not force a stiff or broken control.
- 3Use the local isolation valve if necessary
If water is flowing continuously and the valve is easy to reach, turn it gently to stop supply. Do not force a seized valve.
- 4Avoid dismantling the cistern
Photograph the visible mechanism only if the cistern is already open and accessible. Keep hands away from sharp edges and unfamiliar fittings.
If water is overflowing onto the floor, protect nearby electrical equipment and stop the supply only if the valve is safe to reach. Do not force old fittings.
When to contact a repairer
Contact a plumber if the toilet continues running, the isolation valve is stuck, the cistern leaks, or the flush mechanism is unfamiliar. A prompt repair can prevent water waste and damage.
Useful details to have ready
- Whether water enters the bowl or exits through an overflow
- Whether the flush button or handle returns normally
- Any leak around the cistern or visible isolation valve
Common questions
Can a running toilet increase my water use?
Yes. Continuous flow can waste water even when the leak looks small. If the supply valve is accessible and safe, stopping the flow while arranging repair may help.
Should I replace the flush valve myself?
Cistern mechanisms differ and old fittings can break or leak when moved. If you are not familiar with the system, have a plumber identify the right part and method.
Post the repair job for local workers to review.
Share the job details and postcode area to invite offers. You can still post if no matching repairers are listed, but a quote is not guaranteed.