The problem lies within the syphon housing with a split or broken diaphragm . This is a piece of either oval or circular plastic sheet, depending upon the shape of your syphon, that can be purchased separately. Alternatively , in hard water areas and with for older systems ,you can buy a completely new syphon housing, but measure the height of the old one first, otherwise it might not allow the cistern lid to close. You will need to dismantle the entire cistern on a close couple unit or simply unscrew the large plastic nut underneath the low level cistern, taking care to drain either cistern first.
Maximo, July 2008
