I was having issues of smelly water in a new condo I am renting. I had asked them to do the recommended by you approach of pouring peroxide into the water heater but they would not approve it. So they said they were going to replace the water instead to make me happy cause the only thing storing the water was the heater. The strange thing is that the kitchen faucet and bath faucet seem just fine but the bathroom sink has that strange odor with the cold water. I have poured bleach and peroxide into the drain and it helps for a little while but it returns. What do you think the cause is? I will be getting water filters for all three faucets to be safe. Why only one of them? and do you have a solution for me? Thank you very much!!!
I have also let the water run for long periods of time to flush out.
Hello: The bath sink likely has an overflow built in. These overflows get pretty nasty inside. Make a paper funnel and pour peroxide or bleach into the overflow. It should kill off the slimy things living there and take care of the odor
Hello: The overflow connects to the drain but is different. The overflow is a hole up high on the bowl, usually in the front or back. It is there to prevent one overfilling the sink. The problem with them is there never is a way to clean them out so they fill with smelly black goo.