How Long Does a Furnace Last?

If you have an older furnace in your home, you’re probably wondering how long it will last before you need to buy a new one.

The good thing is that there are visible signs that it’s time to repair your furnace or buy a completely new one. If the control board is flashing a fault code, our Carrier, Lennox and Trane code lists say what it means.

We’ll talk about those later in the article, but let’s first answer the most important question.

How Long Does a Furnace Last?

Figuring out how long your furnace will last depends on a lot of different factors, including how well you have maintained it and when it was manufactured.

If you’re living in an older home and you didn’t pay much attention to your furnace, it’s most likely at the end of its lifespan.

A well-maintained gas furnace typically lasts 15 to 20 years, according to Carrier, though no furnace is trouble-free for that long.

To be completely honest, if you maintain it well – it can last even more than that.

Carrier lists gas furnaces at 15 to 20 years and electric furnaces at 20 to 30 years. For boiler lifespans, see our furnace vs boiler comparison.

When your furnace becomes more than 10 years old, it’s important to give it special attention and to look for new equipment to be prepared when it comes the time to fully replace it.

A great tip is to always choose the right size furnace for your home as you don’t want to buy a smaller or larger unit than you actually need.

A unit that’s too small runs nearly nonstop and wears out faster. One that’s too large turns on and off too often, which also wears it out.

Another great tip is to look for an Annual Fuel Utilization Efficiency (AFUE) rating because it saves energy.

Signs You Need to Repair Your Furnace

The furnace is older than 15 years

On average, gas furnaces last 15 to 20 years, so it’s important to start looking for a replacement around the 15-year mark.

With proper installation and maintenance, a high-quality furnace can potentially reach about 30 years, according to Carrier.

Make sure to check your filter once a month (ENERGY STAR), have a contractor do a check-up each fall, and seal your windows to stop heat from escaping your home.

It becomes very noisy

If you notice that your furnace has become a lot more noisy in the last few months, have it checked.

Some of the most common noises are humming, screeching, clicking, and popping.

All of these noises are connected to different issues, so have a technician find the cause before you decide to replace the furnace. Carrier lists new, loud or unusual noises among the signs a furnace may be nearing replacement.

A space heater can keep one room warm while you wait for a repair, but it is not a substitute for a working furnace.

Higher energy bills

Once the furnace reaches a certain lifespan, it becomes very hard for it to distribute heat evenly throughout your home.

Because it has to overwork to deliver expected results, this can cause a huge spike in your bills every month.

You can do the math by yourself if your bills have risen in the past few months and calculate how much it will cost you if you don’t get a new furnace.

📍 Recommended read: 9 cheapest ways to heat your home this winter.

Furnace flames turn yellow

A well-working furnace always produces crystal-clear blue flames to heat your home.

If you notice that the flames turned yellow, the fuel may not be burning cleanly, which can produce carbon monoxide.

Do not ignore it: shut the furnace off and get professional help. If you smell gas, leave the home and call your gas utility or emergency services, and keep carbon monoxide alarms working on every level and outside sleeping areas.