[blueash]

For those reading this thread, the expansion tank looks like a small propane tank mounted on the top of the water tank. It should have a hollow air filled sound. As it deteriorates water no longer drains from the expansion tank and the tank when tapped with a screwdriver sounds solid. You should when healthy detect a solid sound at the bottom and an empty sound at the top. Had mine replaced but it looked like a do it yourself would have been easy.