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When to replace

When to replace your heating & cooling

Furnaces and air conditioners generally last 15–20 years with good maintenance. Efficiency gains often justify replacing an aging system before it fails outright.

Typical lifespan
15–20 years
Replacement cost
$3,000–$12,000

Signs it's time to replace

  • The system is 15+ years old and needs a major repair
  • Rising energy bills despite normal use
  • Frequent breakdowns or repeated repairs
  • Uneven heating or cooling between rooms
  • Loud or unusual operating noises
Extend its life

Annual tune-ups, regular filter changes, and clean coils keep an HVAC system running efficiently for its full lifespan.

Repair or replace?

When a heating & cooling is aging, the question is whether to keep repairing it or replace it. A useful rule of thumb is the 50% rule: if a repair costs more than half the price of a new unit and the heating & cooling is past the midpoint of its 1520 year lifespan, replacement usually wins. Frequent repairs and efficiency gains push the same direction.

For the full decision framework, see our guide on whether to repair or replace major home systems.

When to replace heating & cooling: FAQ

How long does heating & cooling last?+
Furnaces and air conditioners generally last 15–20 years with good maintenance. Efficiency gains often justify replacing an aging system before it fails outright.
What are the signs I need to replace my heating & cooling?+
Common signs include: the system is 15+ years old and needs a major repair; rising energy bills despite normal use; frequent breakdowns or repeated repairs; uneven heating or cooling between rooms.
Can I extend the life of my heating & cooling?+
Annual tune-ups, regular filter changes, and clean coils keep an HVAC system running efficiently for its full lifespan.
Should I repair or replace my heating & cooling?+
A common guideline is the 50% rule: if a repair costs more than half the price of a new unit and the heating & cooling is past the midpoint of its expected life, replacement usually makes more sense. See our full repair-or-replace framework for the details.

Heating & cooling maintenance tasks