Third Line???

Here’s some polybutylene found today - I see a hot, cold and…Ground? What the hell could the third line be for?


Is there a recirculation pump on the hot water side?

No, but then again, I do not believe that the system is active, although I could not absolutely confirm this due to limited attic access.

Going to a bathroom? H&C to lav & C to WC
Guess you don’t get much freezing weather in Florida :slight_smile: Don’t see a lot of plumbing in attics around here.