5 Reasons For A Broken Or Under Performing Furnace

furnace filter

5 Reasons For A Broken Or Under Performing Furnace

Like everything, problems with your furnace always seem to creep up when you need it most, like in the middle of a frigid day. Since heat has a significant impact on the comfort in your home, it’s important to identify and correct problems with your furnace quickly.

Check out these five reasons for a broken or underperforming furnace so that you can quickly determine the proper steps to take to get your home comfy and cozy again.


Whether there are strange sounds or smells coming from your furnace, or you’re just noticing that something doesn’t feel right with your home’s air quality, a minor furnace problem can quickly turn into a major repair. Many homeowners choose to continue to use their furnaces despite obvious issues, but that will only make matters worse in the future.

While any issue with your furnace should be identified and corrected as soon as possible, the signs of an underperforming or failing furnace generally include:

  • Low heating temperature.
  • Low indoor air quality.
  • Frequent cycling.
  • Irregular airflow.
  • Inconsistent temperatures.

You may also notice that your energy costs skyrocket, though there could be more than one cause for that. Tears or leaks in the air duct system, an incompatible thermostat, an incorrect furnace size and poor home insulation are the main causes, but a furnace in need of repair could also be the reason.

Here are the five reasons for a broken or underperforming furnace:


Your furnace is equipped with an air filter that’s designed to prevent dust, pollen and other airborne particulates from circulating in your home, but it also works to keep your furnace operating efficiently. If a filter becomes dirty enough to prevent proper airflow, it could have a detrimental impact on your furnace’s efficiency and operation.

Fortunately, this is a simple fix. By checking your filter at least once or twice every few months and replacing it as needed, you’ll be able to keep your furnace operating at its best.


While a faulty or incompatible thermostat won’t cause a furnace to fail, it can impact its ability to operate properly. If your furnace is having issues, checking the thermostat is the fastest and easiest thing to do before troubleshooting other elements that may be causing the problem.


If your furnace has a pilot light or electrical ignition system, it could have a malfunction that affects your unit’s function. If the pilot light or electrical ignition system fails, a gas-fueled furnace can’t ignite the burners and can’t produce heat.

Ideally, your pilot light or electrical ignition system should be checked once a year, along with routine maintenance, to be sure it’s operating properly.


The blower motor, or fan motor, circulates air through your home. If it fails, your furnace will still be able to ignite and work properly, but the blower motor won’t be activated and won’t allow air to circulate through your home.

The blower motor is part of a system of components that work together to circulate the warm air, which includes fan motors, belts and bearings. If there’s a problem with the blower motor, any or all of these components may be the cause. Along with your annual maintenance, your blower motor components should be checked for wear or damage.


Furnaces fueled by natural gas can be impacted by issues with the fuel supply line and an inadequate supply of fuel. Gas is volatile and toxic, however, so any issues with a fuel supply line should be addressed by a professional technician.


If you prefer to enjoy the long winter with reliable and consistent heat, it’s much better to prevent furnace problems from creeping up in the first place.

Furnace maintenance from a professional technician can identify any issues that may cause a broken or underperforming furnace by inspecting each and every component for signs of wear or damage. This not only saves you from inconvenient and unexpected failure in the middle of the busy season, but it also helps you save on serious and expensive repairs in the future.

That’s not all, though. Regular furnace maintenance has other benefits, such as:

  • Lower energy bills: A properly running furnace is more efficient, which means that it requires less energy to keep your home at the temperature you prefer.
  • Extended equipment life: Your furnace is a big investment, but regular maintenance can keep it running properly and help it perform at its best for longer periods of time.

At LEGACY, we offer a comprehensive maintenance plan that has its own advantages, such as:

  • 15 percent discount on parts.
  • Guaranteed 24-hour response time.
  • Two complimentary tune-ups, one for your furnace and one for your air conditioning unit, which include a thorough inspection and efficiency analysis prior to the heating and cooling seasons.
  • Filter changes in the spring and fall, as well as email reminders to change your filters during the heating and cooling seasons.
  • Three-year parts warranty on aftermarket parts and a five-year parts warranty on OEM parts installation.
  • 15 percent discount on indoor air quality products and duct cleaning services.


As you can see, there are many possible reasons for furnace problems that can range from a minor inconvenience to a major furnace repair. Fortunately, regularly scheduled maintenance for your furnace can help you prevent these issues before they can inhibit your furnace’s performance in the middle of a cold winter.

If you’re in need of furnace repair or maintenance in your home or business, LEGACY can help. We offer many furnace repair services, such as code compliance of systems, carbon monoxide testing, high-efficiency equipment installation and upgraded filtration systems to help your furnace run smoothly and keep you warm and comfortable. Contact us today to schedule an appointment with one of our certified and licensed technicians and keep your home warm and safe!

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