Should I Replace My 25 Year Old Furnace?


If you’ve never replaced your furnace before and you may have lived in your home for quite some time, there’s a good chance your furnace may be very old. After discovering the system’s age, you may be wondering should I replace my 25 year old furnace? While it may still be working, it’s probably not as efficient as newer models. Welsch Heating & Cooling shares more information on the average lifespan of furnaces, the signs that tell you it’s time to replace a furnace, and the benefits of installing a new furnace system in place of an older unit.

How Long Do Furnaces Last?

The average service life is 15 to 20 years for gas furnaces or 20 to 30 years for electric ones. However, it is possible for furnaces to last much longer than these averages, especially with good furnace maintenance and care. If your furnace’s age is nearing, within, or beyond the average furnace lifespan for its type, it’s time to start making plans for a replacement. Even if your current furnace seems to be in working order, it’s better to get ahead of a furnace replacement rather than waiting for it to suddenly stop working.

Furnace Replacement Warning Signs

Homeowners are often unsure of making furnace replacement decisions because they aren’t aware of the various signs that indicate a new furnace is the best move. While age is certainly an important factor when determining when to replace your furnace, it’s not the only one.

There are a few signs that indicate it may be time for a new furnace sooner rather than later. One sign is an increase in energy bills. If your furnace is working overtime to heat your home, it will use more energy and drive up your bills. Over time, your furnace will become less and less efficient. When you replace your furnace, although it’s a large investment upfront, you might make up the difference quickly with the energy saving you’ll experience with a new unit.

Another sign is strange noises coming from the furnace. If you hear banging, griding, or rattling, it could be a sign that the furnace is overworked and needs to be replaced. Frequent repairs to make your home comfortable could also be a sign that it’s time to replace your furnace. Talk to your repair technician to see which makes more sense economically, making the repairs or replacing your heating system.

Benefits Of Upgrading Your Furnace

While replacing your furnace may seem like a daunting task, moving forward with a new heating system installation project offers many benefits.

  • Furnaces have come a long way in terms of energy efficiency. New furnaces are typically more efficient than older models, meaning that you could see significant savings on your energy bills.
  • When shopping for a furnace, compare annual fuel utilization efficiency (AFUE) ratings to see how much you can expect to save on heating bills.
  • A newer, more efficient furnace will better regulate the temperature in your home, making it more comfortable throughout the winter months.
  • Additionally, newer models come with many features that can improve your comfort and safety. Older furnaces are more susceptible to developing cracks in the heat exchanger which can lead to carbon monoxide leaks. This could quickly become a dangerous situation. With a little research, you can find the perfect replacement furnace for your home.
  • A new furnace will also improve the air quality in your home. If you have allergies or asthma, a new furnace can help to alleviate symptoms by providing cleaner air, circulating fresh air, and reducing dust and allergens in the home.
  • Because furnaces last an average of 15 to 20 years, installing a new one now can help you avoid an unexpected furnace repair bill down the road. New furnaces are less likely to break down, plus you’re covered by a fresh warranty term in case something goes wrong.
  • Finally, a new furnace can add value to your home if you ever decide to sell.

Furnace Replacement Services in St. Louis

25 years is a long time for a furnace to run, and your old furnace will not likely last much longer. A new furnace will provide improved comfort, energy efficiency, and more inside your home. To upgrade your home’s furnace, call Welsch Heating & Cooling today.


Excellent They were very professional. Left the jobsite very clean. Explained the equipment quite well. Walked me through the several rebates. Overall, I cannot think of one bad thing about my experience.


Our family tried 4 other company’s in St. Louis to replace old boiler and three AC units for a 4,500 sq. ft. , 100 year old home. It was a VERY complex project involving a lot of thought and creativity. The project was also completed a week before its expected...


Welsch Heating & Cooling were professional from the first steps to the completion of my project. They replaced two furnaces in my house. The sales rep was trustworthy with the units he recommended. He also pointed out existing ventilation problems that could be a safety concern. The installation crew were...

Marcus P.

I’m not sure if this is the best way to reach you with a big thank you. David and Chris did a great job over the weekend fixing our HVAC system. You guys installed it last November. The thermostat died. I called early Sunday morning and David and Chris worked...

Fritz F.

I could not be happier with my decision to use Welsch.

Jeff C.

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