Posting for a friend, so I don't know all the details.
The problem is the natural gas water heater is producing dirty hot water most of the day (a few days now). The thing is the heater was fine until after a gas related repair was made. Actually, I believe all that was done was the gas was shut off for a few minutes (the water heater pilot had to be relit), so I don't know how that could have caused the dirty water problem. The heater now also makes a strange popping/gurgling sound when it is heating.
Does anyone know what could've happened? Thanks in advance.