Deciding whether to fix or replace a furnace comes down to three main things: age, the cost of the repair, and safety.
Most gas furnaces last 15 to 20 years with good care.
When to Fix Your Furnace
- It is under 10 to 12 years old: Newer systems still have plenty of life left.
- It is under warranty: If parts or labor are covered, a repair is usually cheap or free.
- The fix is minor: Simple fixes like a new igniter, thermostat, or flame sensor cost very little.
- The repair costs less than 50% of a new unit: If a repair is a few hundred dollars and a new system costs thousands, fixing it makes sense.
When to Replace Your Furnace
- It is over 15 years old: Older units break down more often and waste energy.
- The "50% Rule" is met: If the repair costs half as much as a brand-new furnace, put that money toward an upgrade.
- You face a cracked heat exchanger: This is a major safety hazard because it can leak dangerous carbon monoxide into your home. Replace it immediately.
- Your energy bills keep climbing: Old furnaces have to work extra hard to heat your house, which drives up utility costs.
- You need frequent repairs: Constant service calls mean your system is failing. Keep track of these warning signs.