Mystery solved - and totally gross.
Submitted by murph on 6 June 2008 - 12:01pm. houseone
Some of you may recall our complaining about "mouse smell" a few months back, originating from the basement. Mmm, sweet smell of death.
In fact, I disassembled nearly our entire heating system and rearranged the entire basement in the process of trying to figure out where the smell was coming from. No luck. (I was positive it was in a heat duct, since the smell was not there when I woke up that day, but the heat turned on while I was taking a shower, and something started to bake.) It subsided after a week, during much of which we were not-here, but there's been a bit of a lingering aroma.
Fast forward to now. I've got contractors installing a flue liner for our chimney, so that we stop getting condensation through the brick into our walls. Taking apart the furnace and water heater flue leads, the contractor called, "Hey, come here - you're lucky you didn't croak, man."
Yes, boys and girls, mystery solved. Apparently a squirrel managed to fall down our chimney, and then climb into the water heater flue lead - it was the shower that triggered the baking (curing?), not the timer on the thermostat waking up the furnace. In the meantime, well, either our carbon monoxide detector doesn't work or our water heater wasn't putting out enough to kill us. (Comforting? Not really.) I suppose this could be part of why I get sniffly (and somewhat cranky?) when I spend all day at home - I always attribute it to allergies.