How to Fix a Lever Flush Toilet Cistern That Won't Flush

It's a very common and very frustrating issue when it takes multiple turns of a cistern lever to flush a toilet, and without intervention it's only going to get progressively worse over time.

This is almost always indicative of diaphragm washer failure.

Lever flush syphons have what can only be described as a piston-like assembly inside of them. At the bottom of this assembly is a very thin, flexible plastic membrane.

Over time as the toilet is flushed, holes will start to form in this membrane.

This will eventually result in complete failure of the diaphragm washer and the toilet will no longer flush at all.

The good news is that this diaphragm washer is very easy to replace if you have a 2 or 3 part syphon as there will be no need to remove the toilet cistern.

Diaphragm washers can still be replaced if you have an older 1 part syphon, however this will involve the removal of the cistern in order to get to the backnut of the syphon to remove it. In these cases, we recommend replacing the syphon with a 2 part model for easy servicing in future.