Hi all. Does anyone have any ideas on what may be causing the following?- I have a customer who says that their tap water has a metallic taste. This has been happening for about four months after having a new washing machine fitted. They contacted their water supplier who were convinced that it was to do with the new washing machine and suggested fitting check valves. I have since fitted check valves to both the washing machine and the dishwasher supplies but the problem has not gone. Apparently when the water is boiled in the kettle, it tastes even worse. Also, they were thinking of fitting a water filter kit with replaceable cartridge. Does anyone know if theses are any good? Thanks v much.