Whilst all of the fittings in the en-suite drain perfectly well, the family bath drains slowly and the family toilet drains very slowly indeed, with the water in the pan remaining at a level much higher than it should. We've cleaned the bath waste pipe with foam cleaner and I've spent hours working on the toilet, finally taking it completely off the wall today. I pushed a spring auger into the soil pipe, but there doesn't seem to be any obstruction for it to clear.
I'm completely mystified as to why, when they all share the same soil pipe, the fittings immediately adjacent to the soil pipe don't work properly, but those further away are fine. The effect has always been noticeable, but in the last 6 months has become much worse. I'm willing to believe that there is still a blockage in the bath waste, but as for the toilet, I've completely removed it and can see that it has a clear passage to the soil pipe.
Can anybody offer any suggestions? Cheers, Steve