William Keogh
Grant, I have never heard of a Back Draft are you sure you do not mean Back Filling. Well if it is back filling it means that the Water Pressure coming into the Shower for Hot/Cold feeds are uneven and thus one of the feeds is pushing water back down the opposite feed. This usually happens when Cold is on Cold Mains Feed and Hot Water under a Pump or Gravity Feed. To stop it you either put a non-return valve on the weaker feed or balance the two, e.g. Combio System, Twin Impeller Pump, both of Gravity. I hope this helps, Bill Pipe Dreams Plumbing Services, Bournemouth, Dorset
