Toilet doesnt flush correctly

[Felix Da Housecat]

Yeah, I CAN'T SEE ****

I should think so too, who on earth takes a dump in the cistern

 

[Ali195]

Probably just the diaphragm in the siphon has split, dead easy to replace and costs pennies.

Can i just get a new diaphragm from Wilk's or would i need an entire new siphon block?

 

[WillyNelson]

Just take the old diaphragm to you local hardware shop & buy a replacement. Cost me 15 pence last time I did it.

Tie the ballcock up so that the inlet valve stays shut and flush the toilet to empty the cistern.
You should be able to remove the syphon unit by undoing any fastenings and sliding it upwards.
Diaphragm should be a simple clip/screw in from the underside.