How do I fix a running toilet?

A toilet that keeps running wastes a lot of water. The cause is usually a worn flapper, a float set too high or a faulty fill valve inside the cistern.

Lift the cistern lid and watch what happens after a flush.

Check the flapper

If the rubber flapper does not seal, water leaks into the bowl. Wipe it clean or replace it.

Check the float

If the water level is above the overflow tube, lower the float or adjust the fill valve.

Check the chain

A chain that is too tight or too loose can stop the flapper from closing. Adjust it so it has a little slack.

Test for leaks

Put a few drops of food colouring in the cistern. If it appears in the bowl without flushing, the flapper is leaking.