How can I fix my Pacific Dual Flush flushing Valve?

I have a Pacific Dual Flush Flushing Valve and Low Profile Button bathroom suite the foam pan sealer required replacing.
After replacing the sealer and connecting the system together and turned the water back on the inlet valve continually discharges water into the WC pan, the cistern never fills up to the water level as the water continues running out into the pan. When the button to flush is pressed nothing happens. Can this be fixed or do I need to buy another Syphon?