When it gets cold, a furnace can heat air inside a home. Whether a furnace is old and inefficient or no longer working, replacing it can cost anywhere from $2,818 to $6,822, with a national ...

It’s about 17 years old, but still working fine. We don’t want to spend $8,000 to $10,000 for a new furnace just to sell our house. What should we do?

Even if your furnace is still working without these problem signs, any oil furnace that’s more than 10 years old could be running with as much as 30% less efficiency than a new furnace.

After moving in we found that the furnace makes an annoying pop sound after the burner turns off. Contractors I’ve spoken to say this is normal, but our old furnace never did this.