My dad had an issue with the sulfurous odor in the hot water. Certain water chemistry combined with the anode's metal results in that. If you have a magnesium anode, try an aluminum one or vice-versa. Going from magnesium to aluminum solved his issue.
As an alternative you could try one of the electric anode kits. They are considerably more expensive.
As an alternative you could try one of the electric anode kits. They are considerably more expensive.