November 23, 2021

It’s important to know furnace life expectancy because you don’t want it to break down in the middle of winter. Based on our professional experience, most heating systems last around 15–20 years. How long your heating system lasts depends on how often it runs and how often you’ve done regular maintenance.

It’s hard to know exactly when your heating system will go out, but it will start to give you some signs when it’s failing. Some sings you need furnace replacement are more obvious than others, but knowing what to look for can help you avoid any interruptions to your comfort.

We’ll review the top warning signs that your furnace is nearing the end of its lifespan or it’s time for replacement. And we’ll also give you some tips that will help you decide between repair and replacement. That way, you can make the best decision for your comfort and your budget.

6 Warning Signs That Your Furnace is Failing

1. Furnace is More Than 15 Years Old

The average furnace life span is around 15-20 years with annual furnace maintenance. If yours is getting close to 15 years old, you’re getting close to that average life span, so we recommend planning for replacement. This will help you avoid an emergency when your furnace quits for good!

2. Your Home Feels Uncomfortable

An older gas furnace may struggle to keep your home comfortable. You might notice low air flow for heated air, cold air or uneven heating in certain rooms as your furnace ages. Or that your home’s air feels like it has too much moisture. Either way, indoor air quality problems are a sign that your old furnace is on its last legs.

3. Your Heating Bills Are Sky High

Old gas furnaces aren’t as efficient as new ones, which can affect your budget when you’re trying to save money. And they lose energy efficiency as they get older, which means they may have to run more frequently and longer to reach your desired temperature.

With natural gas costs expected to rise 30% or more this winter, having an old gas furnace can cost you, both in monthly energy bills and comfort.


If your natural gas furnace is around 20 years old, it likely has a low AFUE rating. AFUE, or annual fuel utilization efficiency, measures how efficiently your furnace uses natural gas to create heat.

An older furnace is typically below 80 AFUE, which means it wastes more than 20% of the gas it consumes. In contrast, an energy-efficient model is 90 AFUE or greater. In Wyoming, high-efficiency furnaces like ENERGY STAR® models are rated at 95 AFUE or higher.

4. Your Furnace is Unreliable

As your gas furnace gets old, it’s more likely to break down. There’s nothing worse than having it go out during a cold snap or blizzard. So, if you’re calling us for furnace repair often, it might be time to start planning for a new one.

5. Your Furnace is Making Weird Noises or Smells Funny

A typical gas furnace will make some noise as it turns on and heats your home. But some furnace sounds, like screeching, banging or buzzing, are a sign that something is wrong. The same goes for smells like burning plastic or rotten eggs. Whether it’s better to replace or repair your HVAC system depends on the extent of the problems and repair costs.

6. Repair Bills Are Expensive

We generally recommend furnace installation when furnace repairs are more than half the cost of a new system. Major heating repair includes carbon monoxide problems, a cracked heat exchanger or a broken blower motor. If your furnace is less than 10 years old, still under warranty or repairs are inexpensive, it’s best to fix it.

Our Pros Can Help with Your Furnace Installation in Cheyenne

Getting a new gas furnace is a big decision, but our professionals at AC Mechanical are here to make the process stress-free and easy. We’ve offered quality, affordable furnace installation in Cheyenne and surrounding areas since year.

As your local Lennox® Premier Dealer™, we’re proud to deliver the outstanding customer service your neighbors, friends and family trust when they need to replace a furnace.

When it’s time to replace your furnace, your HVAC technician will help you make sense of replacement furnace features that work for your home and budget and give you a free estimate with no pressure or obligation.

And once your new furnace is installed, we’ll give you tips on having a well-maintained furnace so you can enjoy energy-efficient heating for years to come.

Give us a call at 307-778-0515 to request your estimate today.

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