gas furnace that has lasted for 30 years

How Long Does a Furnace Last? And When to Replace It

The average life expectancy of a furnace is between 15-20 years. And, when properly installed and maintained, a furnace can last up to 30 years or more. Pretty impressive right!?

But, a 30 year or more lifespan for your furnace isn’t automatic. Let’s go over the factors that dictate a furnace’s lifespan. You will also learn what you can do to get the most use out of your furnace. And lastly, we’ll give you some tips on when you should replace your furnace.

Factors that Dictate a Furnace’s Lifespan

Furnace Installation

A furnace, like any other machine, operates at its best when it is properly installed and maintained. Some of the common mistakes made during a furnace installation job are:

  • Incorrectly installed or sized ductwork: This can cause a large amount of air to be lost during the heating process because of leaks in the ductwork. This causes the furnace to work harder than it should because it is trying to compensate for the wasted air that escaped from the faulty ductwork. The more unnecessary strain that is put on a furnace, the more its lifespan is hindered.
  • Poor quality ductwork: Not all ductwork is created equal. Poorly designed ductwork can also lead to frequent leaks in the ductwork. This can result in more unnecessary strain on the furnace.
  • Improperly sized furnace: A furnace that is undersized will have to work much harder than it should have to. Because it isn’t large enough for the space it is heating, it is constantly running in order to reach the temperature set on the thermostat. An oversized furnace will have to start up and shutdown more much than it should have to. Because it is too large for the space it is heating, it heats the area to the set temperature quickly with a large blast of heat and then shuts off. This large blast of heat doesn’t usually maintain the set temperature as well as the steady, constant flow of heat that is delivered with a properly sized furnace. Thus, the oversized furnace will start up and shut down more often.
  • Improperly installed or sized vent lines: When a furnace doesn’t have the proper ventilation it needs, the airflow can be hindered which puts strain on the furnace and can even damage it’s components. It’s important to make sure the furnace’s ventilation is correctly sized, installed, and that it has enough clearance to vent adequately.

Furnace Maintenance

Having the correct sized furnace installed properly is the first step to ensuring the longevity of the furnace. But, there’s more. Maintaining the furnace is just as important. Some important maintenance steps to regularly implement are:

  • Replacing the air filter: A dirty or clogged air filter is probably the most common culprit of furnace problems when it comes to neglected maintenance. Neglecting this step can put a major strain on your furnace because it is having to work extra hard to push air through the dirty/clogged filter. Replacing the air filter every 90 days at a minimum is recommended.
  • Professional furnace maintenance: While the average person can change the air filter themselves, we recommend leaving all other preventive maintenance to professionals. This includes inspecting, cleaning, and adjusting the furnace to keep it operating at its peak ability. Regular furnace maintenance is crucial if you want to get the most out of your furnace for a long period of time.

With proper installation and regular maintenance performed on your furnace, it is perfectly set up for the long haul. You can expect peak operation and efficiency out of your furnace for many years to come!

But what if your furnace seems to be coming to the end of its lifespan? What if your furnace is consistently needing repairs, seems to be running rough, or is super old? When is a good time to replace it? That’s the next topic we will cover!

new replacement furnace installed in a garage

When Should a Furnace Be Replaced?

The old adage “if it ain’t broke, don’t fix it” rings true here. If your furnace is running well and is operating efficiently, there’s obviously no reason to replace it. Unless of course you simply want a more efficient furnace, but we will cover that a little later. First, let’s go over some common reasons why you might want to replace your furnace.

Reasons to Replace a Furnace

  • Your furnace is constantly needing repairs: If your furnace is constantly having problems and needing repairs, then it might be time to consider replacing it. As long as you are having proper maintenance performed, the furnace should not be needing repairs on a consistent basis. Instead of throwing money down the drain on repairs, purchasing a new furnace will give you a new, warrantied, more efficient system that should operate with very little need for repair, if any. While a new furnace will likely cost more upfront, it’ll save you money in the long run.
  • Your furnace is 15 years old or more: If your furnace is 15 years old or more, it’s probably a good idea to at least consider the idea of replacing your furnace. Most furnace warranties are good for 10 years. After that, all of the expenses for repairs fall on the homeowner/business owner. Also, furnaces that are 15-20 years old aren’t as efficient as furnaces that are manufactured today. A more efficient furnace equates to money saved on the energy bill. But, as we said earlier, if it ain’t broke don’t fix it. If your furnace is old but is operating well and doesn’t seem to be causing a major increase on your energy bill, it’s wise to stick with it!
  • You want a more efficient furnace: As I just mentioned in our last point, furnaces produced today and much more efficient than those of the past, especially those 15 years or older. Furnaces today can be up to 98.5% efficient (AFUE). Furnaces produced 15 years ago were topping out at an 80% efficiency rating. That’s a large gap in efficiency which can result in huge savings on your energy bill. In some cases, the money saved by switching to a more efficient furnace can actually pay for the new furnace over time.

Is Your Furnace at the End of its Lifespan?

If your furnace is showing signs that it’s nearing the end of its lifespan, it’s time to start shopping around. Do your own research and find out what you need. Get numerous free estimates from local HVAC companies and they can advise you in what type and size furnace that you need. In many locations the cost to replace a furnace starts at around $1,500.

If you live in Jackson TN or the surrounding areas, give us a call at 731-300-1030. We’d love to come out and give you a free estimate!

Do you have any experience with furnaces lasting an abnormally long period of time? What’s the longest a furnace has lasted that you know of? Comment below!

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