How Long Will My Furnace Last?

Published on: November 18, 2013

When the chilly winter weather takes over, it often causes people to think about the condition of their furnace. Having a heating system in place that can be relied upon and will keep your home comfortable is essential. “How long will my furnace last” is often a question homeowners ask, particularly when another cold season hits.

While that’s really a question that can’t be answered with one simple answer, there are some general factors that can help you get an idea about how long your furnace will last. In order to become a savvy consumer, you should learn some basics regarding furnaces and what impacts their operation.

Furnace Basics

A furnace warms air and distributes it throughout your home, typically with a duct system. Furnaces made today are far more efficient than they were 20 years ago. Such energy-efficient models can save you money on your monthly utility bills, are greener than older types and can help improve the indoor air quality in your home. However, regardless of what kind of furnace you have or how old it is, the most important thing to determine how well it will withstand the test of time is its heat exchanger.

The Life a Furnace Heat Exchanger

The heat exchanger is like your furnace’s heart. Once it stops working, so too will your furnace. While most parts of a furnace can be easily replaced, it’s a much more serious predicament when the exchanger fails. It can create an unsafe environment, and therefore must be replaced right away.

Older furnaces that were made with heavy metal heat exchangers, like cast iron, have been known to last 30 to 40 years, but they’re also known for being energy drainers. Forced air furnace heat exchangers have an average life expectancy of 15 years, with a range typically between 13 and 20 years. Most heat exchangers used in models today today will last between 15 and 25 years and are usually made from aluminized or stainless steel. It’s inevitable that the constant heating and cooling of a heat exchanger’s metal will eventually cause it to crack, become corroded or otherwise fail. But there are things you can do to help extend its life. 

Extending Your Furnace’s Life

While no furnace will last forever, the following are steps you can take to help keep it running in tip top shape for as long as possible:

  • Schedule annual maintenance appointments with a qualified HVAC contractor. According to the U.S. Department of Energy (DOE), a well maintained system will make it more efficient and is also critical for ensuring healthy indoor air and extending its life. 
  • Keep the moisture levels in your home in check. If the amount of moisture becomes excessive, it can cause the exchanger to rust, thus speeding up the degradation process. 
  • Change your filters regularly. If your air filter is constantly clogged, it not only decreases your indoor air quality but also restricts airflow. That may cause the exchanger to overheat and also means your furnace has to work even harder to to deliver the conditioned air within your home. In general, check your air filter monthly and replace it as soon as dirt begins to build up.
  • Make sure the A/C coil is always clean. When you have an air conditioner and a coil on the top of your furnace, the drain can become clogged and leak condensation on the heat exchanger if you don’t keep it cleaned. This can result in a rusty heat exchanger and may even destroy some electrical components.

Replacing Your Furnace

If an expensive component or several parts of your furnace need replacing, it may be more cost effective to purchase a new one. In that case, you should take every step possible to improve your home’s overall energy efficiency first, so you’re able to save money and buy a smaller unit. Look for a furnace with the Energy Star logo and high efficiency ratings

If you’re thinking “how long will my furnace last,” now’s the time to contact HVAC professionals for an inspection. Contact us today to find contractors in your area