Just learned today that my 32 year old hot air, natural gas furnace which is in the attic and supplies heat to 4 bedrooms and 2 baths isn't working because there are two cracks in the heat exchanger (pilot blew out because of this, per gas man). Apparently I need a new furnace. Gas company estimate was $3600 for a "Comfort-Aire," 80% efficient, horizontal flow, from 75,000 to 100,000 BTU's (old one was 105,000 BTU but gas guy said I could get by with about 80,000). This price is for the unit, installation, permits, and 2 years free service. I don't know the length of the guarantee but he said most of the horizontal flow units have a life span of about 10 years. There is no duct work to be done other than what is involved in removal old unit and attaching the new one. There is no air conditioning involved in this.
The price sounds high to me, but we do live in Massachusetts and costs here are egregious. I'm told that the replacement furnace is a "middle-of-the road" furnace. He said Comfort-Aire is the same furnace sold under the names Ruud or Rheem or Conquest.
I know nothing about furnaces. Any recommendations about this furnace, other brands, reasonable price, etc. would be appreciated. I don't even know any good non-gas company guys to call here. We repeatedly get burned with high plumbing costs (e.g. $400 to remove and replace one outside faucet for the water hose, took 15 minutes, honest!)