by mplayer78 »
Tue Jun 11, 2019 8:03 am
I have a slow draining basin which feeds into the bath and shower waste then under the concrete floor then through another u-bend to outside. The bath and shower drain with no issue however the basin (which is obviously the highest) has always drained slowly. Weirdly, however, when I run water down the bath the basin drains much quicker. I have change the trap to an anti-siphon type but it doesn’t seem to help much. Any help would be much appreciated!!