I've not done any decorating or used anything like that. The smell seems to come from sink and water and overflow. I jhave used a natural cleaner (fizz and use- which is like a non chlorine bleach powder including bicarb of soda) also tried Mr Muscle drain cleaner but smell is still there. I had a plumber fit new taps yesterday and he put a pressure reducing valve in utility room (this was because then shower knob was too stiff for me to turn on and he said it would help) but now even my kitchen sink water smells funny (not exactly the same smell, I am guessing it's the newnesss of the thing he fitted, but now I have no water that's OK. He said the water for whole house now goes through that pressure reducing valve, should I have it removed? (although the bathroom sink had the weird smell before that was fited) what else can I do, I can't use the bathroom its so bad, I am using downstairs loo.

The pressure reduceing valve should have an adjust valve on it so u can change the psi's for more water pressure but for the oder in your faucet do you have well water or city and if you have well water was your well detaminated