How long does a gas furnace last?
A gas furnace typically lasts 15 to 20 years. Where yours falls in that range depends on how it was installed, how hard it works and how well it's maintained.
When will yours need replacing?
Enter the install year to see when replacement is due.
Opens the free calculator with this item filled in.
What affects its lifespan
- Filter changes: clogged filters strain the blower and heat exchanger
- Annual service and cleaning
- Correct sizing for the unit
- Climate and hours of use
Signs it's near the end
- Rising repair calls, especially ignition and blower parts
- Uneven heat or short cycling
- Rust or cracks on the heat exchanger
- Climbing gas use for the same comfort
Questions
- How long does a gas furnace last?
- Typically 15 to 20 years. CapexClock uses 18 years as its default, and you can change it for your building.
- When should I start saving to replace a gas furnace?
- As soon as it's installed. Spreading the cost over its 15–20 year life keeps the replacement from landing as a surprise. The mini calculator on this page shows a monthly amount for yours.
- How is a gas furnace priced in the calculator?
- By default it's priced per unit. Enter your own quote or recent invoice; CapexClock never fills in costs for you.
Plan every replacement in your building
List your roof, HVAC, water heaters and more to get a 10-year forecast and one monthly reserve number.
Open the free CapEx calculatorOther hvac lifespans
- Central AC / condenser 12–15 years
- Heat pump 12–15 years
- Boiler 20–30 years