The water out of my hot tap smells positively rancid, but only at the weekend. All throughout the week there is no problem. I live in W. Kent. Is this something I just have to live with? Is there something the water company isn't telling us?
I would suspect that something has fallen in your header tank and died (e.g. a squirrel or bird).
Maybe the through put of water during the week, stops the build-up of smell, which becomes apparent at the weekend.
Take a look in your loft and check the header tank for foreign matter which could be causing the problem � although to be honest, you should also notice this in the upstairs cold-taps which are fed from the header tank.