There are no details of what model number it is, but it won t flush unless the button is positively pushed. I ve taken the top of the cistern off and as I only recognise the standard cock and ball system anyway, there seems nothing actually broken or out of place. The transparent tube that goes from the button onto a rubber grommet seems sound. I m not a great DIYer, so simple term,clear help would be appreciated...please?

Clive, January 2013