Evaluate & Compare
Repair or replace your furnace?
How to decide whether to fix or replace the furnace in your Des Moines home before an Iowa winter — weighing age, repair history, and safety, not a sales pitch.
For a furnace, start with the $5,000 rule: multiply its age by the most recent repair cost. Around $5,000 or more — or a furnace past its roughly 18-year average life — usually favors replacement. But furnaces add one factor an AC doesn’t: safety. A cracked heat exchanger can leak carbon monoxide, so it’s a replace-now signal regardless of the math. Run your numbers below.
Repair-or-Replace Calculator
Should I repair or replace my furnace or AC?
The fastest gut check is the $5,000 rule: multiply your system’s age in years by the cost of its most recent repair. If the result is around $5,000 or more — or the unit is past its average service life — replacement usually saves money over the next few years. Below that, a repair often still makes sense. In Des Moines, IA, a system that struggles through a summer heat wave or a deep-winter cold snap is also a strong signal to plan ahead.
Replacement is usually the smarter spend
The math points to a new system saving you money and headaches over the next few years.
- Age x last repair cost is about $7,200, at or above the $5,000 rule of thumb for replacement.
- At 12 years it is near the end of the ~14-year average service life.
- Occasional repairs are normal as a system ages, but they add up — track the trend.
Common misconception
“It is always cheaper to repair.” Not when repairs stack up. A 15-year-old system limping through an Iowa summer can cost more in back-to-back repairs and high energy use than a new, efficient unit would over the same span — and an R-22 AC leak alone can rival the price of replacement.
Signs it’s time to replace the furnace
- It's 15–20+ years old. Gas furnaces average about 18 years. Past that, a major repair is usually money poured into a system near the end of its life — and efficiency has improved a lot since.
- A cracked heat exchanger. This is a safety issue, not just a cost one. A cracked heat exchanger can leak carbon monoxide, and on an older furnace it almost always means replacement rather than repair.
- Repairs are stacking up. Frequent breakdowns — especially in the dead of an Iowa winter — usually cost more over a couple of seasons than a new, reliable furnace would.
- Rising bills or short-cycling. Climbing heating bills, uneven warmth, or a furnace that switches on and off rapidly all signal a system that's struggling to keep up.
When a repair still makes sense
- It's under about 12 years old. A younger furnace usually has years left, so a single repair is the smart spend.
- It's a routine, inexpensive part. Igniters, flame sensors, and capacitors are normal wear items — quick, affordable fixes, not a reason to replace.
- It's been well maintained. A furnace with a clean service history and no safety concerns is worth keeping going.
Furnace running but the air feels cool? Start with furnace blowing cold air, and if you decide to replace, see what affects installation cost.
Iowa myth vs. truth
Myth: “An old furnace is fine as long as it still lights.”
A furnace can light and still be unsafe. Cracks in the heat exchanger develop with age and heat cycling, and they can leak carbon monoxide even while the burner looks normal. That’s why an annual safety check matters in Iowa, where furnaces run hard all winter — and why “it still turns on” isn’t the whole story.
Emergency service
No heat in your Des Moines home?
A failed furnace in a deep-winter cold snap can’t wait. All Seasons HVAC answers quickly with emergency HVAC service across the Des Moines metro, and can give you an honest repair-or-replace recommendation on site.
Common questions
Should I repair or replace my furnace?
Use the $5,000 rule: multiply the furnace's age by its most recent repair cost. Around $5,000 or more — or a furnace past its roughly 18-year average life — usually means replacement saves money. A younger furnace needing a routine part is almost always worth repairing. The calculator on this page helps you weigh it.
What is a cracked heat exchanger and why does it matter?
The heat exchanger is the metal chamber that separates combustion gases from the air you breathe. A crack can let carbon monoxide into your home, so it's a safety issue first. On an older furnace, a cracked heat exchanger usually means replacement rather than repair.
How long do furnaces last in Iowa?
Plan on roughly 18 years for a gas furnace. Iowa winters work a furnace hard, but annual maintenance — including a safety check of the heat exchanger — helps it reach the top of that range.
Is a no-heat furnace in winter an emergency?
It can be when temperatures drop below freezing and pipes are at risk. All Seasons HVAC offers emergency HVAC service across the Des Moines metro, so a winter no-heat call doesn't have to wait until morning.