"Doctor D." wrote in message
I am currently installing a vanity unit sink to replace a pedestal
sink in our en suite.
I have connected the waste to the existing 32mm stub using a pushfit
to solvent weld connector and a new bottle trap via a 90 degree
The water runs from the sink very slowly indeed. I have held the
garden hose running flat out over the waste pipe below the bottle
trap and it copes with the flow, as did the previous sink. I am
wondering if the new sink for some reason can't suck air back
quickly enough to drain the sink at a reasonable speed. I have
plugged the sink and brim filled it and the overflow operates very
slowly. (it is possible to overfill the sink with both overflow and
plug hole open!)
I can hear glugging as the water drains, and the water can be heard
trickling down the vertical drop below the bottle trap moving very
slowly. I have tried swapping the bottle trap for a P trap but this
made no difference.
Has anyone any ideas on this please. I was wondering if anyone
markets a vented trap to allow air to be sucked in - but I suspect
this would let water and smells out!
Did the old sink have an overflow and the new vanity sink doesn't ?
If this is the fault, then you'll need one of these :
It's called an anti-siphon bottle trap and it allows air to flow back
into the waste pipe and stops the suction from the water flowing down
the pipe, sucking all the water out of the trap.
By coincidence I just had to fit one of these to daughter's bathroom basin
but this was to stop smells because water in trap was being depleted by
another drain on same waste run. £4.14 in B&Q