I'm sick today, so I took the day off, and, too tired to shower, decided to take a nice relaxing bath. I turned the "hot" tap and then it POPPED OFF AND HIT ME IN THE FACE AND A TORRENT OF SCALDING WATER STARTED SHOOTING OUT everywhere.

I sprinted down into the garage to turn off the water pressure, and noticed that shit was leaking out all over the place down there with decent pressure. I turned it all off and it subsided, but now everything in my house is really really wet (and very very warm, as it was hot water).

WTF just happened, and how do I fix it? I called a plumber but who knows when he'll call me back, or if he'll even be bothered to show up before monday.

HALP PLZ.

I'd suspect a pressure regulator somewhere has failed. I'm not sure about how the plumbing works in a home without actually looking around myself, but that's what it sounds like to me.

I'd say safety valve as well, did it look like it was coming from the water heater directly or was there a burst pipe joint?

Perhaps it was something with your bath/shower. If you always take showers there may have something wrong with the bath mechanism you didn't know about.

No it was the actual hot water faucet. It turns out that it just got unthreaded somehow, and the additional leaking was due to an overflow of the waste lines from all that pressure.

Problem solved, hopefully.

Yeh, and they usually have a spring, which explains why it popped off