Toilet flush issues

[PracticalTacticalBrilliance]

Hi,
We have a siphon toilet system and for a while now it's taking a couple of goes with the handle to make it flush. Sometimes it seems like the handle is going to get stuck in the down position and at other times the mechanism inside of the cistern hits the top of the cistern when it flushs. It all seems to work fine without the lid on.

It doesn't have what I would call a chain connecting it to the flush lever, its more an s shape piece of metal. There's no ballcock either, or nothing that looks like one.

Any ideas on how to sort it out or is this one for a plumber?

Thanks!

post some photos of the inside of your cistern please. And stand back and show it from the side including the pan.

I expect the syphon diaphragm is worn. It almost certainly means the cistern has to come off. I expect the cistern screws are rusted solid, which makes it hard.

look on the bright side, if you had a concealed one built into the wall and tiled over, it would be fifty times harder.

I'd suggest fitting a new flush valve. The Flapper system is extremely simple and gives a good forceful flush.

Thanks, I hope these help. I genuinely can't take a picture from the side, it's a very small space.

We had a leak in it last year & it was fixed, with the cistern removed, in October. The plumber also lowered the water in the cistern as it was too full and kept running after it was flushed. The flush issues have happened since then.

It seems to work of if you flush it while pressing down on the lid of the cistern.

I see yoiu have a new fill valve (in place of a ballcock) but the syphon looks old. I'm pretty sure it will just be wear and tear, and a worn or leaky diaphapgm. They can be replaced, but I'd just go for a new flush valve.

This kind gives a very good flush. It is also quiet. It has hardly any moving parts and can be operated with a L-shaped handle like you have. It flushes with just light finger pressure on the handle. Fluidmaster is a good brand.

There are various other modern models. They can often be replaced from above without taking the cistern off, some of the old-style Dudleys can as well, but in your case, I am pretty sure the cistern will have to come off.

I think that siphon might be a metro rapid where it is possible to release it from the cistern in order to replace the diaphragm without having to take the cistern off the wall.

A split or ripped diaphragm is the most likely cause of the flush losing power. I replaced my old siphon with a 2 part one precisely to avoid having to take the cistern off the wall of the diaphragm went

Thanks very much!

Well spotted!

I see the blue nut now.