I recently purchased a house with an 80 gallon solar water heater that is 15 years old. My problem is that rust colored water flows for the first 30 seconds whenever I run the hot water. I have gotten mixed advise from the plumbers I have talked to. Some say that all the unit needs is to be drained well. Another says that I need a new unit.
I have tried draining the unit twice but after a day, the rust water reappears. Is there a good way to drain/clean a water heater? Or am I stuck purchasing a new one.