After running my bath tub’s hot water for about ten minutes, the faucet is ejecting 1-2 second streams of black particulates, every few minutes. This is happening consistently after running the water for 10 minutes or so. It only happens when running the hot water.
This is happening in a 10 year old, United States high rise, with what I believe is a tankless water heating system. I haven’t been able to reproduce the same results from any other faucets in the unit.
What could these black particulates be from?
Here’s a video: https://vimeo.com/246658414