Been there myself, spent half a Saturday chasing down a leak that ended up being a tiny crack hidden behind the pipe bend. Definitely frustrating, but...

Funny you mention that humming sound—I had something similar happen with my place. Kept hearing this weird low hum whenever I'd run the shower, though...

Yeah, learned that lesson the hard way when I moved into my new place last year. Thought I'd save time online, but the address change threw everything...