Did you run the fan during the summer to circulate the cold air from the basement up to top floor?
Probably the dust that settled on the heating coils. Same happens with stove-top or oven elements that haven't been used for months, the dust settles on them. Once the dust burns off, see if there still is a smell.
It could be under warranty, in which case go to the company that did the installation (along with the paperwork). You'll still have to pay for the annual maintenance, but the warranty could cover both labour & parts (usually different lengths of time), depending upon how old the furnace is. Once the warranty is up, you could go with some other company.
Furnaces have a life expectancy of 20 to 30 years.
That is a great tip too, but I am pretty sure it is out of warranty and I wouldn't be able to find it even if I wanted to --- I moved into the house about 13 years ago and I figure it was maybe at least a few years old then, so I figure it is probably about 15 years old or so.
Try to look for the plate or sticker with the installation date. Might be inside one of the covers.
If you think it needs a new furnace, see if you can find a place with no interest for one year (pay off before the one year point). If bought my furnace and AC like that, paying off before the year was over. For example, see link.
Well, my parents used Lancaster Heating and Cooling in Hamilton for a furnace and air conditioning installation and were very happy. Only catch is that I don't know if they come out as far as Toronto for an installation, not to mention a repair, but who knows. Contact info is: Phone: 1-877-388-4282. Address is 195 Hempstead Drive, Hamilton, ON L8W 2E6. Web is www.lancasterheatingandcooling.com
Another company that I don't know as much about so you will have to check them out yourself is Toronto Air Conditioning & Furnace Repair. As I did a quick Google search they certainly had the most professional website and compelling in how they described themselves, and the way I figure it, if they put that much work into looking good, then that is an okay start in my book. Contact info is: Phone: 416-962-5678. Address is 305-35 Ormskirk Ave., Toronto, ON M6S 1A8. Web is www.acandfurnace.com