by plumbbob »
Sat Jul 26, 2008 9:22 pm
I guess you could if you could find one to fit, but the problem is caused by the w/m pipe not being high enough to stop the water from back feeding into the w/m.
As your arrangement worked before, it stands to reason that it should still work without a non return valve.
Make sure the pipe runs from the trap right up to the underside of the worktop before leading back down to the w/m.