The good news: You know those carbon-monoxide alarms you can get combined with your fire alarm? Well, mine work, as they went off last night (both of them). I changed the batteries before going to bed, thinking that was the problem - and also opened the doors to let in the sauna-air, just in case.
The bad news: This morning, on a hunch, I looked into the utility closet and discovered that the vent atop the gas-fired water heater had slipped off. Odd; has the house settled that much? Then I noticed water around the bottom of the water heater... seems it's about to blow, not only leaking a bit but also settling in a discomforting way.
Great month for this discovery: This is the month I don't get paid, and also the month I pay for my vehicle tabs, taxes, and insurance. *sigh*
Fate, you are mean-hearted.