We have a Bradford White 50 gallon water heater and it was done working at 6.5 years. We could not get it to drain after doing all the steps that you find in the manual because it was so clogged with sediment . We needed to take a pretty sturdy,but flexible ziptie and stuck it in the drain valve and reamed it to finally loosen blueish green sediment. It worked like a charm. We could not believe how clogged it was. Then it took approx. 30-45 min to drain.