Glugging syphon

[nozydog]

I just installed a new Flomasta dual flush syphon in my concealed lever operated cistern. Works great and flushes well but once the cistern has almost filled you hear a single glug every few seconds for about a minute! It's coming from the pan but definitely not the waste/soil as there are no bubbles and I have flushed using a bucket of water (also that would happen long before the cistern is full) the noise is clearly coming down the pan feed pipe from the syphon! No air bubbles rising in the cistern during the glugging either.... just can't make this out! Anyone experienced this?

 

[ShaunCorbs]

Yep standard you will find it’s the water breaking the vacuum eg not siphoning anymore