I have the same issue: spurt of black, oily-looking water when turning on the hot water faucet in a tub, shower, or sink. It doesn't happen all the time. Our electric hot water heater was 30+ years old, so we changed it out a few days ago, but had the black water again today in the shower. We don't have braided lines, so the solution "gefact" found won't work for us. We're hoping old sediment in the pipes, from before the water heater was changed out, is still being released and will eventually resolve itself. In the meantime, should we be worrying about the safety of drinking water from the common pipes? Thanks!

Hi sherchers and welcome to The Plumbing Page on AMHD.
You piggybacked on a 6 year old dead thread so I gave you one of your own. Before you post look in the upper left hand corner for the date..
Are you on a pump or city water? Are there black particles throughout the house or just the bath? Back to you, Tom

We're on city water. The black water has been seen in both bathroom tubs/showers and in the kitchen sink. It only happens occasionally and only when turning on the hot water tap. When we replaced the hot water heater recently, we also replaced the copper flex line connections from the water heater to the house plumbing. Thank you for your quick response!