A well-maintained HVAC system lasts roughly 15–20 years. As it ages, the repair-versus-replace math shifts. Watch for these five signs.
1. It's 15+ years old
Older systems are less efficient and often use refrigerants that are being phased out, making repairs pricier every year.
2. Rising energy bills
If your bills are climbing while your usage hasn't, your system is working harder to do the same job — a classic sign of declining efficiency.
3. Frequent, costly repairs
A common rule of thumb: if a repair costs more than half the price of a new unit, replacement is usually the smarter spend.
4. Uneven temperatures and humidity
Hot and cold spots, or a house that never quite feels comfortable, often mean the system can no longer keep up with your home.
5. Strange noises or smells
Grinding, rattling or musty odors can signal failing components. Get them checked before a small issue becomes an emergency in peak season.