sdavido was home today, and he noticed that the house was getting rather cold. Turning up the heat and adjusting the radiators didn't seem to have any effect. Fortunately we have a totally awesome plumber, who was able to wedge us into his already-hectic day. After a bit of experimentation he found the problem: The thermostat had blown. SD- says that when the plumber took the old one off the wall there was a scorch mark. Wow. I didn't even know that was possible. Apparently it wasn't installed right. (Not a surprise, unfortunately.) So now we have a shiny new thermostat, with a little patch of old wallpaper next to it (which we'll patch eventually)... and heat! Yay for things that work!