Repair or Replace? How to Decide on an Aging Furnace

There is no single rule that answers this, but four questions get you most of the way there. Work through them honestly and the answer is usually obvious.

1. How old is it?

A gas furnace in Minnesota typically runs 15 to 20 years. Under 12 years, repair is almost always the right call. Past 18, you are maintaining a system that is living on borrowed time, and parts availability starts to become its own problem.

2. What does the repair cost against a replacement?

If a single repair approaches a third of the cost of a new system on a furnace that is already past 15 years, replacement usually wins — especially once you count the repairs likely to follow it.

3. How is it running between repairs?

• Rooms that never reach the thermostat setting
• Rising gas bills with no change in the weather
• Frequent cycling on and off
• Noise that was not there two winters ago

4. What would a new system actually change?

A high-efficiency furnace paired with the right ductwork changes how the house feels, not just what it costs to run. If you are also weighing a new AC, replacing both at once is usually cheaper than two separate projects and gets you a properly matched system.

When you want a second opinion, we will give you a straight answer — including when the right answer is to keep the furnace you have.