30 year old furnace

[Mary R.]

The gas furnace in a house I'm buying is 30 years old. From what i've been told by neighbors, and from what I see of the building--haven't had it inspected yet--the owner had it 26 of those years and took good care of the house.
Should I expect to replace it soon? Will a new model make a difference in the gas bill? Since this has been (probably) well taken care of, might I expect low maintenance/parts replacement and gas bills if I keep this one for a few more years?
Would you just go ahead and replace it, or pay for an inspection first and go from there?

[Steve Babiak]

Ah, "life expectancy" and usefulness are two different things. There are many furnaces that I have seen that are way older than 30 years old, and they were working just fine; sometimes those old-timers really knew how to build good stuff. I agree that "life expectancy" for a furnace is ~ 18 years; so, since this is beyond the life expectancy, I would make certain I have "reserve funds" set aside to cover the replacement of the unit when it dies. But until then, in a rental, if it ain't broke ...

And I would first make certain that it really died. Last month, I had a nearly 20 year old boiler that stopped producing heat. Turns out the pilot wouldn't stay lit. That just means it needed a thermocouple, around $10 at the home improvement stores and replacing one of those is truly DIY. New system can wait IMO.