Wow, this thread almost slipped me by! Better late than never, I guess. Excellent posts by all. There are only a couple of points I can add:
- In Ontario, you can no longer buy a forced-air gas furnace under 90% AFUE.
- There are rebates available from the Provincial Government and the Ontario Power Authority (OPA) to upgrade your furnace. A home energy audit is required, (which will cost you ~$350.00), but you could qualify for up to $940.00 in rebates.
- Most manufacturers also have rebates available.
- If you are truly moving within the next couple of years listen to John:
AFAIK the big selling feature is "new" furnace, not "fancy" furnace.
Conversely, if you are staying in the house, the multi-stage gas valves and ECM motors are WELL worth the extra money.
With regard to the quoted "Savings" on fuel costs, it really depends on the age and efficiency of the existing furnace. I have seen consumption cut in half in a number of installs, but it is not common.
Also, since you are moving, don't get talked into spending more on one of the higher end name brands. Even a cheap-o builder furnace will be relatively trouble free for the first 5 years if installed correctly. Please note that I will give the exact opposite advise if you are staying in the house long term.