toilet won't flush

[sarebearmeeks]

since installing a shower pump the toilet will not flush. The water is coming through fine powered by the pump but I can't get any suction. I don't know if there is supposed to be any suction coming from the piston or syphon box thing. I have taken the handle off and if I tug on the piston pushing it down and up several times forcefully - it will flush. Do I need to replace it?

 

[Burnerman]

If the cistern is full of water, then there's no connection between the new pump and the flushing.
The syphon unit in the centre of the cistern has a polythene diaphragm which will have split.....some diaphragms are available on their own, but often enough its a complete new syphon for a tenner or so.
If your loo is close coupled it'll have to be split to replace the syphon.
John

 

[seco services]

Sounds like the diaphragms split in the base of the syphon.