This is our first winter in our house. So far, the furnace (oil burning, probably about 10 years old, I'd guess) seems to have been running smoothly. The only change we've made was about two weeks ago when we started using the timer on the thermostat, setting it at 68 when we wake up, 55 during the day, 68 during the evening, and 60 during the night. Before that, we had been setting it manually: 68 at morning and evening, low 60s during the day and overnight.
Last night, we noticed a smoky smell, mild but still noticeable. I wouldn't describe it as an oily smell, though; it was definitely more "woody." There was no smoke or soot. Same thing in the basement: same smell, no smoke, no soot. I'm not even 100 percent sure it was coming from the furnace, because the odor wasn't much stronger in the basement than it was in the living room. Plus, there was a similar smell outside the house, and it seemed to be stronger there.
I convinced myself, temporarily at least, that the smell wasn't coming from our furnace or house and went to bed. But then we woke up to a cold house this morning. When I went downstairs and checked the furnace, I found that the power switch had flipped off. I turned it back on, and the furnace seemed to be operating normally as far as I could tell, producing heat and no odor (although it was on for only 45 minutes before I left for work). But now the smell from last night combined with the switch flipping off has me concerned.
My questions are
1.) Can a furnace flip off the power switch automatically like that? And if so, why? Is it the sign of a bigger problem?
2.) Can a furnace make that kind of smell? If so, what could be causing it?