I have a 5 year old gas hot water heater using city water in a large metropolitan area. (Detroit). Over last 3-4 months I have gotten what looks like semi-hard white flakes particularly when hot water hasn’t been used in a few days. The flakes can be broken up with your finger and are hard white crusty. They are starting to plug all of my faucet screens. What can be causing this?
Sounds like your hot water heater dip tube just gave up the ghost.
Contact the manufacturer and get reimbursed for not only hiring a licensed Master Plumber to install a new dip tube But to flush out your lines and replace your now plugged up T&P valve.
If you have any problems contact consumer affairs.