Toilet constantly running or trickling
Not sure if this matches your problem?
Use our interactive tool — answer a few questions and get a personalised diagnosis.
Most likely cause & what to check
Remove the cistern lid and observe — check if pushing down the rubber flap stops the running.
If pressing the flap stops it: the flap valve is worn. Turn off the water supply, flush to empty, and replace the flap valve (£3–£8).
If water is running into the overflow pipe: the fill valve isn't shutting off. Try bending the ball arm downward slightly.
If adjusting doesn't fix it, replace the fill valve (£10–£20).
🛠 Tools & materials you may need
🔗 Some links above are affiliate links — if you buy through them we earn a small commission at no extra cost to you. This keeps the site free.
Get a vetted local engineer to handle it — no hassle, Gas Safe registered.
Was this guide helpful?