You press the button or pull the handle, and nothing happens. Or there's a weak little trickle instead of a proper flush. A toilet that won't flush is usually a problem inside the cistern, and you can often fix it in a few minutes.
First, lift the cistern lid
Take the lid off the cistern and put it somewhere safe on a towel. It's heavy and breaks easily. Now look at the water level.
If the cistern is empty or low
- Check the isolation valve on the pipe going into the cistern. It may have been turned off. Turn the slot so it's in line with the pipe.
- Check the rest of the house has water. If not, see no water or low pressure.
- The fill valve may be stuck or blocked. Jiggle the float arm gently. If water starts flowing, the valve needs cleaning or replacing.
If the cistern is full but nothing happens
- Lever toilets: check the link between the handle and the flush mechanism. A broken or unhooked link is very common and easy to replace.
- Push-button toilets: check the button is connected to the flush valve. Cable or air-tube buttons can come loose or wear out.
- The flush valve or siphon may be worn. On older toilets the siphon diaphragm splits, so you have to pump the handle several times. It needs replacing.
If it flushes weakly
- The water level in the cistern may be set too low. Adjust the float so the water stops 2 to 3 cm below the overflow.
- The bowl may be partly blocked. See how to unblock a toilet.
- Limescale can block the small holes under the rim. Cleaning them with a descaler helps.
When to call a plumber
If parts are hard to reach, the valve won't turn, the toilet is leaking onto the floor, or it's your only toilet and you need it working tonight, call us. Also see our guide to a toilet that keeps running.
Common questions
Why won't my toilet flush?
Usually the cistern isn't filling, or the handle or button has come loose from the flush mechanism. Lift the cistern lid to check.
Why does my toilet only flush if I hold the handle down?
The siphon diaphragm or flush valve is worn. It needs replacing, which is a quick job for a plumber.
How do I fix a weak toilet flush?
Raise the water level so it stops 2 to 3 cm below the overflow, and clear any limescale from the holes under the rim.