Most of us do not think about replacing our furnace or heater until it’s too late. The temperature begins to fall in the house well below the thermostat setting, and we realize the furnace has died. Could we have seen this emergency coming? And how often do you need to replace a furnace? Here are several factors to consider when you think about replacing your furnace.


On average, a well-maintained furnace lasts 15years or longer. You’ve scheduled annual maintenance checks and changed air filters regularly, but do you know how well the previous homeowner maintained the system? Experts recommend replacing a furnace that is 15 years or older. With the advances in technology, a new system will likely provide greater fuel efficiency than an older furnace.


Have your energy costs risen? Perhaps your current system can no longer handle your heating needs. Have you remodeled your home and added square footage? You should consider the additional burden on your furnace, and consult an HVAC professional to determine if your current system can meet the challenge.

Are your furnace repair costs growing, too? As a furnace ages, repairs become more expensive. If a repair bill for your heating system reaches 50% of the cost of a new furnace, you should consider replacing it with a new high-efficiency model. For a furnace nearing 20 years old, replace it when the repairs reach 10% of a replacement.


According to ENERGY STAR, the Department of Energy’s efficiency certification program, the high-efficiency furnaces rated in 2020 increase energy efficiency over standard furnaces by 20% to 22%. Standard furnaces operated ‘on’ or ‘off.’ They turned on full speed to reach the temperature indicated by the thermostat and turned off when they achieved the desired result. The on/off cycling of the furnace burned additional fuel and strained the system.

Today’s most efficient furnaces use a variable speed approach, changing operating speed according to the need, shifting into a lower gear for maintaining temperatures and using higher speeds to bring the temperature up to the desired level. Added benefits include a quieter mode of operation as well as more even heating of the home. Check with a reputable vendor about tax credits available to homeowners purchasing more efficient systems.

How often should you replace a furnace? In general, consider replacing a system 15 years or older. But pay close attention to cost and efficiency as well as age to determine if it’s time to replace your heating system.