Furnace repair costs depend on the issue and how extensive the problem is. If you detect something is wrong and call the professionals on time, you can save some money. On average, you can expect repairs to cost around $250 if the issue is not too complicated such as sealing minor leaks in the duct work. For relatively serious problems, this may increase to $400.
If it’s something major, and the problem has been neglected for too long, it could easily cost $1000 or more. And if the issue is beyond repair, you might have to consider replacing the furnace rather than spending money on frequent repair services.