On Tuesday, August 16, 2016 at 8:14:04 PM UTC-4, bd wrote:
replying to trader4, bd wrote:
And the valve could eventually fail
I looked at expansion tanks today, and in the instructions it plainly states
that the tank WILL eventually fail. Given that both of my hot water heaters
are inside my home and in places where a flood of water would be destructive
and potentially VERY expensive, I think that I could dump a little water every
now and then.


Do you even have a closed system? Most people don't because they are
either connected to a municipal water system with no backflow valve
or similar or a well that has a pressure tank.