January 10, 2023


Furnace in St. Louis, MO

Knowing the average lifespan of a furnace will help you prepare for essential heating system upgrades in your St. Louis, MO, home. Although many HVAC professionals assert that furnaces last between 15 and 20 years, actual lifespans can vary quite a bit. How furnaces produce heat, how they’re installed, and how well their supporting ductwork is maintained are all important factors to consider. Read on to find out more.

Fuel Combustion and Its Impact on Furnaces and Furnace Lifespans

Most furnaces combust fuel to produce heat. These include oil-fired furnaces, natural gas-fired furnaces, and propane-fired furnaces. All others provide indoor heating solely through the use of electricity.

Although fuel combustion doesn’t necessarily shorten the lifespans of furnaces, it can lead to greater wear and tear. This is especially true if these units aren’t correctly maintained. Furnaces that use combustion to produce heat also have more components than electric units, connected venting systems, and other factors that increase the likelihood of problems. Fortunately, no matter what type of furnace you own, you can always extend its lifetime through timely repairs and by scheduling annual maintenance service.

How Long Do Gas-Fired Furnaces Last>

Whether using propane or natural gas to produce heat, gas-fired furnaces have an estimated lifespan of about 15 to 20 years. Proper installation and adequate care will ensure consistent and efficient performance for close to two decades. However, once these heaters reach their 15-year mark, it’s time to start budgeting and preparing for replacement. At this time, homeowners will often notice:

  • Significant increases in their home energy bills
  • Longer heating cycles
  • Hot and cold spots throughout the building
  • A marked decrease in indoor air quality

Many gas-fired furnaces are capable of functioning several years beyond their 20-year mark. However, these last years of service are usually plagued by recurring repair issues and efficiency-related concerns.

The Lifespan of an Electric Furnace

Electric furnaces are expected to last between 20 and 30 years. Their lifespans are largely impacted by sizing, installation, and ongoing maintenance. For instance, although an electric furnace may be capable of providing three full decades of reliable performance, if it is too large or too small for the intended service area, it will likely fail long before this time. You should maximize your investment by ensuring your furnace has the capacity to handle your heating needs and schedule regular maintenance from a trained technician.

How Long Will an Oil-Fired Furnace Last?

Oil-fired furnaces are expected to last between 20 and 25 years. Although oil-fired furnaces are becoming increasingly less common, these units are built with incredibly durable parts, and they provide a number of impressive benefits. Unlike gas-fired furnaces, oil-fired models often have cast iron heat exchangers that hold up well under constant use.

Given their potential for longevity, oil-fired furnaces are fairly easy to forget. Between managing fuel tank refills and general heating oil tank maintenance, some homeowners fail to make advance preparations for eventual replacement. One easy way to track an oil-fired furnace’s lifespan is by watching its tank. Indoor heating oil tanks usually last about 25 years. An outdoor heating oil tank has an average lifespan of 20 years. When it’s time to replace your heating oil tank, it’s probably also time to have an HVAC technician inspect your furnace and make recommendations for replacing it.

How Your HVAC Air Ducts Can Impact Furnace Longevity

The type of furnace that you have in your home, how well you maintain it, and whether or not it was correctly sized and installed aren’t the only factors that can affect its longevity. In fact, in a forced-air heating system, one of the most important factors pertaining to general wear and tear and eventual furnace failure are HVAC air ducts.

The average lifespan of HVAC air ducts is about 15 to 20 years. However, if your air ducts are already 15 years old and you’re on deck for a furnace replacement, you should probably have your ducting replaced too. Ragged, torn, improperly sized, and all-around inefficient air ducts can place an extraordinary amount of stress on your heater. Damaged ductwork can restrict airflow, cause static pressure issues, and force your furnace to work much harder than it should. When HVAC ductwork is in poor condition, furnaces that are rated to last 20 years could fail after just 10 years of service.

Signs Your Furnace Is Ready for Replacement

No matter how long your furnace is expected to last, there will come a time when replacing it is unavoidable, and this time may come much sooner than you think. Furnaces tend to become increasingly noisy as they advance in age. They also take longer to heat homes up. If your furnace has a brand-new air filter and was recently serviced, it shouldn’t have to run constantly to keep your home at a comfortable and even temperature.

Central heating systems that aren’t zoned for customized comfort and increased efficiency are designed to heat homes uniformly. Most have a single, central thermostat that’s used to control the temperature throughout the entire building. If this is the setup in your home, you shouldn’t have rooms that are ice cold and rooms that are excessively hot.

Take a look at your home energy bills from year to year. If you’re paying far more to heat your home this year than you did in years past, this is a sign of natural furnace aging and the resulting decreases in efficiency. Even with regular maintenance and timely repairs, furnaces gradually lose their ability to efficiently convert fuel into heat. If you haven’t altered the size or layout of your home, the size of your household, or your general usage habits, dramatic changes in your furnace’s performance paired with higher energy bills are probably age-related.

It’s definitely time to schedule furnace replacement service if you’re constantly having to pay for repairs. Major furnace repair projects often occur with increasing frequency as furnaces get old. We can help you calculate your cumulative repair costs over time so that you can compare these with the costs of having a newer and more efficient model put in.

Additional Tips to Extend the Lifespan of Your Home Heating System

The first way to ensure that your furnace has a long lifespan is by having it properly sized and installed from the very outset. Professional furnace maintenance should be scheduled once each year and ideally just before the start of the heating season. To further limit the likelihood of problems, it’s important to change your HVAC air filters out once every one to three months.

Finally, even seemingly minor furnace issues should be brought to the attention of a licensed HVAC professional. Strange odors and strange sounds should always be reported early on. This gives our team ample opportunity to catch and correct small problems before they can spiral out of control.

Contact Us Today

Scott-Lee Heating Company is proud to offer a full range of installation, maintenance, and repair services for heating and cooling systems. We also provide indoor air quality solutions, geothermal products, and ductless mini splits. Our business has been offering first-class HVAC solutions to the St. Louis area for more than 40 years.

If your furnace is nearing the end of its lifespan, we can help you find the perfect replacement for your home. Call Scott-Lee Heating Company today to get started.