What to ask about water pH?

[Corpsie]

For mod-con boilers, what type of info should I get from a contractor about my water and compatibility with the heat exchanger?

There seems (from what I've read here) that some water types are better for aluminum heat exchangers and other types for stainless steel: Is this correct? It's confusing to me because wouldn't acidic or basic water attack each heat exchanger in a similar way?

[beenthere]

No , acid, and alkaline water has different effects on SS and aluminum.

You want your PH to be neutral.

[Corpsie]

So the installer will do whatever it is to make the water in the system pH neutral?

or if my city water is crappy, am I SOL?

[beenthere]

Depends on your contractor.

Thats why we stay, forget about the brand, the installer/contractor is more important.