How Often Do You Need to Replace Your Furnace?

homeowner replacing furnace filter

Most homeowners will have this same question at one point or another, especially if you bought a home with the furnace and air conditioning system already installed.

Q: How often does a furnace need to be replaced?

A: The quick answer is that most furnaces last 15-20 years with regular annual scheduled maintenance, and minor repairs along the way. 

The longer answer however, is that furnaces can fail much sooner or last even longer based on the factors discussed below.

How to Get the Most Years from a Furnace

These tips will maximize furnace longevity.

Start with Buying a Good or Higher Quality Furnace

Most brands make basic, better and best lines of furnace. Lennox, for example, has the Merit line (basic), the Elite line (better) and the Dave Lennox Signature Series (best). For Carrier, the progression is Comfort, Performance and Infinity as the top line.

Basic furnace models often fail before 15 years, and many of the best furnaces make it to 25 years with TLC.

The marks of a quality furnace include:

    • Warranty: A Lifetime heat exchanger warranty and 10-year general parts warranty indicate better quality than 20-year heat exchanger and 5-year parts warranties.
    • Cost: As a rule, you get what you pay for. Take two 100,000 BTU single-stage furnaces. The $1,500 Trane is probably going to last longer than the $750 Direct Comfort, though maybe not twice as long.
    • Brand Reputation: Trane/American Standard, Carrier/Bryant and International Comfort Products brands like Heil, Day & Night and Arcoaire have the best reputations in the industry. Lennox’s reputation has slipped in the last 10 years. Goodman’s reputation has improved since Daikin purchased the brand in 2012 and began upgrading quality.

In addition to the warranty, brand and cost factors, higher quality furnaces are going to have more advanced features that provide you with better AFUE, or efficiency, as well as features like variable rate fans, burners, and other advanced features that lower cost units just don’t offer. These features will not only provide higher comfort levels, but allow the furnace to operate at peak efficiency for longer periods.

Have it Installed by a Certified and Experienced Professional

There’s a saying in the HVAC world that a furnace’s most important day is the day it is installed. There’s wide agreement among manufacturers and furnace contractors that whether the furnace was installed properly is the single most important factor in how long it will last.

For example, you could purchase a top of the line Carrier or Trane furnace, and if it’s installed by someone without the proper certifications, or if you skip the inspections, it may only last a few years in your home.

Request written estimates from several HVAC companies in your area. Insist on having permits pulled and inspections completed after the installation. That alone will weed out most of the contractors who are known for performing less-than standard work.

Once you narrow you list, choose an installer that gets high ratings and good reviews from other homeowners. Google reviews, the Better Business Bureau and Yelp can be good sources for ratings and reviews. The best installer probably won’t be the cheapest option. But if furnace reliability is important to you, quality installation is worth paying for.

Keep Your Furnace Properly Maintained

Having your furnace cleaned and tuned on a regular, annual basis will help maintain its efficiency and durability. Most professionals recommend having this service done every year in the fall, though 2-years may be suggested if you live in a climate where the furnace is used less often, or if’s brand new.

Many HVAC companies offer annual maintenance contracts, aka service contracts, for $99-$225 per year. Cost is based on how many components (furnace, AC, air purifier, etc) are part of your system and whether perks are included in the contract.

Perks might include discounts on repair or replacement parts and labor and priority scheduling – meaning that if your furnace breaks down, you’ll be placed ahead of customers who do not have a maintenance contract.

In most cases, annual furnace maintenance only takes about an hour or two, and they will clean the furnace as well as test all functionality and components. A carbon monoxide test and report should also be a standard of any furnace maintenance.

Reasons to Replace your Furnace

These are common reasons homeowners choose furnace replacement over repair:

    • The furnace is 10+ years old and has recently, or already required costly repairs.
    • It was improperly sized, and your home isn’t adequately heated.
    • You want to upgrade to a more efficient furnace or one with better performance such as staged heating and a variable-speed fan.

The Bottom Line

  • A high quality home furnace should last 15-20 years, when it’s been properly installed, permitted and inspected by a quality HVAC contractor, and properly maintained throughout it’s life.