“Should I keep fixing my furnace or AC, or is it time to replace it?” And here’s the honest answer: If your equipment’s getting up there in age, the cost of repairs starts making less and less sense — and the numbers back it up.
1. Age Isn’t Just a Number
Most furnaces and AC units are designed to last about 15–20 years. Sure, some hang on longer, but that doesn’t mean they’re running efficiently or reliably. Once you’re past that mark, even small repairs become a bad investment.
Example:
Let’s say you’ve got a 17-year-old furnace and you spend $400 on a new gas valve this winter. That might get you one more season, maybe two. Do the math:
- $400 ÷ 2 years = $200/year
Now compare that to a brand-new system: - $4,000 furnace ÷ 15-year lifespan = $266/year (and that’s before factoring in improved efficiency and zero repair costs under warranty)
That $400 repair doesn’t look like such a win anymore — especially when the next breakdown could cost even more.
2. Stacking Repairs: Death by a Thousand Cuts
Most aging systems don’t fail all at once — they bleed you dry a few hundred dollars at a time.
Example:
Let’s say over a 5-year stretch, you make these repairs:
- Blower motor: $550
- Control board: $400
- Flame sensor & igniter: $250
- Misc. service calls: $300
Total: $1,500
Now, add rising energy bills from poor efficiency and the fact that the system could still fail catastrophically. That same $1,500 could’ve gone toward a new unit with a 10-year parts and labor warranty — and no more surprise costs.
3. The Hidden Cost of Waiting: Inflation
HVAC systems don’t get cheaper with time — they get more expensive. Between manufacturer price hikes, labor rate increases, and tighter environmental regulations, waiting to replace your system often costs more than just the repair bill.
Example:
Let’s say a new system costs $8,000 today. At a conservative 4% annual price increase, that same unit will cost:
- $8,000 × 1.04⁵ = $9,728 in 5 years
That’s $1,728 more, just for waiting — and that doesn’t include any of the money you’ll likely spend on repairs while holding out.
4. Efficiency Pays for Itself
New HVAC systems use significantly less energy than models from even 15 years ago. That can translate into serious savings on your utility bills.
Example:
Let’s say your old AC has a SEER rating of 10, and your new one is rated at 16 (which is common now). That’s a 60% efficiency improvement.
If your summer electric bill is $300/month, that could mean:
- ~$120/month in savings × 5 cooling months = $600/year
- $600 × 10 years = $6,000 in energy savings over a decade
That’s three-quarters of the cost of a new system paid back in utility savings alone.
Final Thought: Math Doesn’t Lie
If your system is over 15 years old and racking up repair bills, don’t just ask “Can I get another year out of it?” — ask “What will that year really cost me?”
In many cases, replacing your old furnace or AC isn’t just smarter — it’s cheaper in the long run. You save on repairs, lower your utility bills, add value to your home, and avoid the stress of unexpected breakdowns. It’s not about spending money — it’s about stopping the financial bleeding before it gets worse.