How Long Will My Furnace Last? When Should I Replace It?

September 12, 2021

Everything has an expiration date. When something is important, or expensive, extending its lifespan as much as possible is beneficial and preferable. Do you know the expected lifespan of your furnace? Or what you can do in the meantime to upkeep its functionality and longevity?

How Long Will My Furnace Last?

One question we hear all the time is “how long will my furnace last?”. While this is a difficult question to answer since there are so many factors at play, we can provide you with some information on average furnace lifespans, furnace replacement signs, some ways you can delay the inevitable.

Average Furnace Lifespan

While some furnaces can last over 40 years (extremely rare), the average lifespan of a typical gas furnace is around 15-30 years. As long as you have scheduled yearly furnace maintenance, your furnace should easily last over 15 years.

Here are some factors that will affect how long your furnace will last:

Make and model of the furnace (newer systems have longer lifespans than older units).
Frequency and quality of furnace maintenance. In order to maintain manufacturer’s warranties and keep your system clean and efficient, schedule fall furnace maintenance every year from a licensed HVAC company that also fully cleans your system. Learn more about professional furnace tune-ups.
Moisture levels and proper ventilation. Too much moisture can cause heater components to rust and premature breakdowns. Moisture is especially harmful to your heat exchanger.
Proper installation. According to Energy Star, over half of all new HVAC systems are improperly installed. As a result, rated efficiency levels can be reduced as much as 30% and can lead to premature breakdowns, comfort problem, and insufficient air distribution and dehumidification. The most important day of your furnace’s life is the day it is installed.

As you can see, many factors play a role in how long your furnace will last. No one thing will be able to tell you how long your furnace will last (age, tune-ups, humidity levels, installation).

Should I Replace My Furnace?

When it comes to furnace lifespans, there are simply too many variables to give a definite answer. Speak with a professional to help determine whether you should replace your furnace or not.

Homeowners with furnaces over 15 years old, however, may experience greater savings in the long run by replacing their system rather than continuing to spend more money on repairs. Older furnaces tend to be extremely inefficient and can cost you hundreds of extra dollars on fuel and operating costs.

According to the U.S. Department of Energy, homeowners can expect a good return on investment by replacing a furnace with an annual fuel utilization efficiency (AFUE) rating lower than 80% with a new 95% efficient condensing furnace.

Upgrading a furnace that is older than 15 years old with a new high-efficiency unit is a great way to save money and increase home comfort and efficiency. High-efficiency furnaces have an AFUE rating between 90% and 99%, condensing flue gases to a second heat exchanger to reduce the amount of wasted energy. This helps convert nearly all of the fuel to useful heat for your home.

One common rule that people follow when it comes to repairing or replacing something is the 50% Rule — if the repair is over 50% of the cost for a full replacement, go with the replacement.

Learn more signs that it’s time to replace your furnace.

Of course, the decision to replace your heating system is a big one. It’s essential to find a good HVAC company to do the installation for you. Contact Service Champions to discuss your repair and replacement options before making a decision.

Life Expectancy of Common Heating Systems:

Furnaces: 15-30 years
Boilers: 15-30 years
Heat Pumps: 15 years
Active Solar Heating: 20+ years
Electric Heating: 20+ years

Source: U.S. Dept. of Energy

Want to extend the lifespan of your unit? Factors to consider:

Equipment quality — The quality of the individual unit that is installed can predict how long a system will run. Work with your professional HVAC company to determine the best grade unit for your home, needs, and goals.
Annual maintenance — Professional maintenance, once in the spring and once in the fall (between harsher-weather months), is absolutely vital to extending the lifespan of any heating system. Annual tune-ups and cleanings will ensure that the system and all its mechanical pieces are operating smoothly and efficiently. A well-maintained unit will last years beyond a system that is not.
Use — How often do you use your heating system? In a colder climate, or depending on preference, you may depend heavily on your heating system. A unit that is used often is more likely to wear down. Systems that are used often should be maintained often as well in order to slow the effects of use.
Humidity — Due to location, we definitely feel the effects of humidity in the air. A furnace is subjected to rust in high humidity. Control the humidity levels in your home in order to decrease moisture and protect the furnace from rust.
Clean filters — Clean filters lead to happy heaters. During the winter months when the furnace is running more than usual, filters should be changed monthly. When a filter is dirty, it restricts air flow. This restriction can lead to overheating and even damage to the heat exchanger and other components in the unit.