I have a Roca dual flush, close coupled toilet cystern which appears to be letting by in the form of ghost flushing into the bowl. After flushing the inlet valve opens but along with the water there are air bubbles emanating from the bottom of the inlet, and the water flows into the bowl as fast as it enters the cystern resulting in a continuous flow and no flush volume. I can fill the cystern using a shower head and all is well until the next flush, but my guests aren't too impressed with this procedure????? Some people are just too picky.....
Any guidance would be very welcome.
frank.