Quote Originally Posted by chem geek View Post
Perhaps he meant "corroded" rather than rusted. Copper can corrode producing green to blue to black substances.

The key would be determining if the corrosion was from inside the pipe going out or from the outside of the pipe going in -- something that could be seen by examining the section of pipe that failed. The former would be corrosion from the pool water while the latter would be corrosion from condensation in the heater.
Yup, as a plumber there is a huge difference to us between rust and corrosion.

My thoughts still stand re a possible minor pipe section replacement compared to replacing a whole heater.

If it did fail after 6 years, they must have use something like 15 to 17 gauge pipe which is thinner than the "DWV" drainage copper, we used to use or perhaps a section popped open which is not uncommon with cheap, thin pipe.

Wow could I tell stories about the wrong pipe being used in certain applications.