It's almost certain the syphon flap has torn (thats the white thing) and needs replacing.. Do not use an opella make replacement (see my question) I had the same problem and now have to replace it for a 3rd. time..in as many weeks...
Thank you BUCK51 - I thought it must be a problem with the syphon - can anyone recommend a good one as Opella seems to be stocked everywhere round here..
The toilet stopped flushing so I replaced the syphon with a new Opella multiflush. (the old one had a torn flap). The new one worked fine for a few days & then would not flush again.? I again put in a new one (they are very cheap) and again it worked fine for a few days & now will not flush ...