I had the same problem, and I believe that the tainted water has a lot to do with local water authorities (chemical dosing)---we went down to chester cc site, last Feb, got set up and then the inevitable cuppa----- tasted awful,----departed after a few days, flushed and "miltonised2 the system at home---tested using our domestic water. tasted fine, a week later we were off to Holland and France---water was fine for the whole three weeks, came home, about 10days later, went up to coniston----kettle on and yuk!! tried water direct from the service point and yuk again!! bottled water for the rest of the trip.