While there isn’t exact timing on how long a furnace should last, understanding the factors that influence furnace lifespan and recognizing the signs that your furnace should be replaced is crucial to making wise decisions.
Average Lifespan
The average lifespan of furnaces is 15-20 years. However, lifespans vary among the different types of furnaces. Gas furnaces can last 15-20 years, boilers can last 15-30 years, heat pumps can last about 15 years, and electric furnaces can last 20-30 years. If you have scheduled annual furnace maintenance, it should easily last over 15 years.
Consider replacing your furnace with a high-efficiency unit if it’s more than 15 years old. Furnaces with the ENERGY STAR® logo are typically 15 percent more efficient than standard furnaces, which results in energy-cost savings for you.
Factors that Affect Life Expectancy
There are several factors that can affect the lifespan of your furnace:
Maintenance: Dirty furnace components, such as a dirty filter or fan blades, force the furnace to work harder. Regular maintenance and consistent filter changes can help extend performance and improve how long furnaces last. It’s recommended to hire a professional HVAC technician for regular cleaning and tune-ups. They can fix minor repairs to improve performance and avoid bigger issues down the road.
Quality of Installation: Poorly designed, sized or sealed ductwork can restrict airflow, causing problems with furnace performance and reliability. Inaccurately installed venting can also affect performance and reduce furnace lifespan. Professional installation by a qualified technician is crucial to a long-lasting furnace.
Furnace Size: An inaccurately sized furnace installed within an HVAC system can affect the comfort and energy efficiency of your home. Plus, it potentially reduces the furnace lifespan. A larger-than-necessary furnace runs shorter cycles as the home quickly reaches the thermostat’s temperature setting. The frequent turning on and off puts additional wear and tear on the furnace. A smaller-than-necessary furnace runs longer cycles as it struggles to produce enough heat to reach the setting. Long cycles also adds additional wear and tear on a furnace.
Thermostat Settings: Adjusting your thermostat beyond the recommended temperature can cause your system to run excessively long cycles, which, over time, may lead to wear and tear and shorten the lifespan of your equipment. The U.S. Department of Energy recommends setting the thermostat at 68 degrees Fahrenheit when you’re home during the day and lowering the temperature when you’re away from home and sleeping.
Signs Your Furnace Needs Replacing
Frequent Repairs: Multiple furnace repairs within a few years reveal that the furnace is failing, and a significant repair or breakdown is imminent. It’s best to replace your furnace if a repair costs more than half the cost of a new furnace. In addition, if your furnace takes a long time to turn on, it may be a sign that it’s starting to fail.
Strange Noises: If you notice your furnace running louder than normal or developing sounds you are not used to hearing, it is a good idea to have a professional HVAC technician check your system for pre-mature failures.
Age: Start by checking the age of your furnace. If you’re like most homeowners, it’s likely your furnace was already in place when you moved into your home, which means it could be at the end of its lifespan. Locate the owner’s manual or look up the system’s serial number that should be located on the furnace itself. Old furnaces are less energy efficient and more expensive to run.
Increased Energy Bills: A rise in energy bills can mean that your system is running less efficiently.
If you’ve noticed any of the above signs from your furnace, it’s critical to speak with an HVAC professional to discuss replacement options. Problems with your furnace can lead comfort issues in your home, inconvenient failures, or potentially health issues from carbon monoxide if components in your furnace are damaged.
How to Extend the Lifespan of Your Furnace
Maintaining your furnace ensures it lasts years longer with more affordable energy use. Here are some helpful steps to extend the lifespan of your furnace and keep it running more efficiently.
Replace Filters Regularly: Over time, air filters become blocked with debris, obstructing ventilation and making your furnace use more effort. This can cause more problems and sometimes more serious issues.
Ensuring Proper Airflow: To ensure proper airflow, make sure your ducts are sized correctly. A professional will know the correct size but a good rule of thumb is to have 400 cubic feet per minute of air flow for each ton of cooling capacity. You can use a ductulator to determine the right size. Keeping ductwork clean and properly sealed/repaired will prevent leaks and heat loss. If your ducts are undersized, your HVAC system will have to work harder to heat or cool your home, which can increase your utility bills and shorten the life of your HVAC equipment.
Routine HVAC Maintenance: Annual maintenance from a certified HVAC professional will help your furnace last longer. A technician inspects, services, and optimizes your equipment for its best performance. A professional tune-up is a proactive approach to preventing potential issues and breakdowns before they occur by identifying and resolving minor problems early on, saving you more money on repairs and energy bills.
Thermostat Settings: A programmable thermostat gives you greater control over your home’s comfort with features like scheduling automatic setbacks while you’re away or asleep. This helps reduce system runtime, lower energy costs, and extend the life of your equipment. The Lennox S40 Smart Thermostat takes efficiency to the next level by learning your daily routine and creating a customized schedule. It keeps your home comfortable when you're there and saves energy when you're not, using its Smart Away® Mode to optimize operation for peak performance and energy savings.
Insulation: Keeping your home properly insulated and sealed can help by preventing thermal loss and cold air infiltration, which can put strain on your system.
Choosing the Right Furnace for Longevity
There are several other factors to consider when choosing the best furnace for your home. Here are a few factors to help choose one that will last longer.
Energy Efficiency Rating: Furnace efficiency is measured by annual fuel utilization efficiency (AFUE). This percentage tells you how much of the fuel is converted into usable heat. For example, a 95% AFUE furnace converts 95% of its fuel into heat, with only 5% lost. A higher AFUE rating means the furnace is more efficient and can reduce energy bills. Furnaces with the ENERGY STAR® label meet or exceed federal efficiency standards. While a high-efficiency model furnace may cost more upfront, the energy savings over its lifetime often justifies the investment. Some Lennox furnaces are ENERGY STAR® certified, which may qualify you for federal energy tax credits and local utility rebates.
Proper Size: Choosing the right size furnace is crucial. A furnace that's too big or too small won't last as long. A professional HVAC technician can perform a load calculation, which considers the square footage of your house, the insulation value of your windows, the amount of insulation in your walls and roof and many other factors, to determine the right size for your home.
Brand and Reliability: Choose a reputable brand known for reliability and good customer service. Look for furnaces with solid warranty coverage, typically 10 years or more on major components. Lennox is known for their reliability, performance and high-efficiency models. They are some of the most efficient and quietest heating systems you can buy. They’re engineered for perfect warmth and savings.
Maintaining your furnace prevents breakdowns, improves long-term performance and can extend its lifespan. If it’s been a while since your last heating tune-up or if you’re looking for customized recommendations to maximize your furnace, please reach out to your local Lennox pro.
