rebuild

If you go look at your water heater, it will probably have a little valve on the side connected to a pipe that goes down to the floor. That's a pressure relief valve: if the tank ever acquires too much pressue (steam, over filling for some reason, etc) it's designed to let go and release water rather than compromising the tank. Apparently it also works if the water tank freezes up.

As I mentioned yesterday, we had an inch of water (or so) in our furnace room, and about 1/4 to 1/2 inch of water in our laundry room (and out into the hall). I couldn't figure out quite where all that water had come from. While the pipes did freeze (more later) there just wasn't enough water in them to cover that much area (I'm pretty sure). While water may have leaked from the outside (the wall was wet near the bottom, but that was probably from the puddle inside: the wall around the chimney was dry), it does appear the valve on the water heater tripped.

As to the pipes bursting, a pipe in the upstairs bathroom probably burst, a pipe above the hot water heater appears compromised, and the pipe right after our water main enters the house froze. So, an interesting situation. We'll have to see exactly how much of the floor and walls we get to rip up.