If it's not one thing it's three others.
In the last month, I've had to pay for a new wheel bearing for the car and a new water heater. Yesterday, the chronic sinus infection I've been just living with ramped up to the point where I couldn't take it any more so I went to the doctor. I can't quite tell if I have a cold on top of it or not, but I decided that I was sick enough I could pamper myself by turning the heat up. (I keep it pretty cold usually, because not wasting energy is the right thing to do and because LP is expensive.) And nothing happened.
I'd noticed that the furnace was acting flaky a couple of days ago. It would start whirring, the gas would come on and light, and then it would turn off after a short time, flashing an error code. (It uses coded flashes of a single LED to report what's wrong when it has a problem; there's a chart on the front.) This error code seems to be some sort of a problem with exhaust pressure. (It combines several seemingly distinct problems.) It's reporting the same code now, but it's not even whirring and starting the gas. It's not terribly cold in here yet -- about a degree below where it was set before I turned it up -- but since it doesn't seem to be working at all now, I'm sure it will be soon.
So I called the furnace guy. He's doing an install now, and he won't be finished until 4 or later. Great. I'm supposed to be walking birder2's dog at 4 and then gaming this evening. But furnace guy is in the middle of a job now, and booked solid for tomorrow, so if I don't want to be really cold by Friday, I have to rearrange my day. I can feed Maggie a bit early. I just hope that this is a fix-in-one-visit problem, not a you-need-a-new-furnace problem.
ETA: So, I rearranged my day to be home when the furnace guy could be here. I got my groceries, cut my malamute visit short, walked Maggie earlier, and ran home, to discover that the furnace was running happily. Based on the temperature, it had just started, but it ran most of the next hour, and it's now so decadently warm that I could take off my long sleeved shirt. So I talked to furnace guy, and decided that he didn't need to come by for an emergency call any more, but he will try to fit in a non-emergency visit for a long-overdue tuneup and figure out what its problem is.