I recently read a reply to sulfer smell in hot water only and the solution was anode rods. Can you tell me if that's a job I can do on my own and what would the cost be and where to purchase. Have been a carpenter and remodeler for thirty + years, but haven't run in to this yet.
A hot water only odor is caused by bacteria, usually sulfate reducing bacteria using the anode rod to cause H2S gas. But iron and manganese reducing bacteria can also cause H2S in the hot water. Removing or replacing the rod with another type material prevents that but if IRB/MRB are the cause, you have to kill them. Raising the temp of the water to 140f for a few hours kills all bacteria in the water.
Removing a rod can be a real character building experience. They are very tight and there are no handles on the tank, so an impact type hammer drill etc. works best. Removing a rod can cause some of the material of the rod to come off and fall into the tank. If that happens, it's as if you didn't remove the rod. And then you're left with chlorinating the heater but that only stops the problem for a period of time until the bacteria regain control.
So increase the temp for a couple hours and see if that stops the odor, if so it proves bacteria are the cause. Bacteria come in with the cold water from the well, so you need to use a disinfectant like chlorine, ozone or hydrogen peroxide or continue to sanitize the tank periodically. A UV light will not work due to the release of iron etc. into the water as the cell ruptures; IOWs you create another problem in solving one.