Just spent the better part of my Sat draining and flushing my 40 gal gas water heater. Got about two quarts of solids out of it! The boiling and popping sounds are now completely gone. As far as I know, this is the first time it has been done in the 15yrs since it was installed. Dan, If you have an electric water heater, you might try putting in reduced wattage elements. That will increase the recovery time, but also reduce the noise and amount of flushing required. Good luck!