How Your Clogged Air Filter Can Seriously Damage Your Furnace

Air filter replacement is not at the top of most people’s home improvement project lists. And while conventional wisdom holds that you should have your furnace and HVAC system serviced at least once a year, too many of us simply forget to do it.

However, neglecting your air filter can result in serious problems that can jeopardize your health and safety and cost you a pretty penny to fix. If you have a forced-air system, the kind most commonly found in residential homes, your home’s temperature is adjusted through warm or cool air that is blown through the ducts in each room. Simultaneously, your HVAC’s fan pulls air out of these rooms towards a heat exchange where it is warmed or cooled and then blown back through your house. This process continues until your home’s temperature is adjusted to your liking.

A clogged air filter obstructs this process, making it more difficult to heat or cool your home. And if you’ve neglected your filter, you’re likely to face one or more additional problems.

What Kind of Problems Can a Clogged Air Filter Cause?

Because a clogged air filter is less efficient in regulating your home’s temperature, it requires more energy to do so. In fact, the U.S. Environmental Protection Agency estimates you may consume as much as 15% more energy with a dirty filter than with a clean one. You’ll start to see your monthly energy bill increase the longer you neglect your air filter.

The quality of the air in your home will also decline. As your forced-air system recirculates air that passes through the filter, dust and debris will also circulate. While you can’t see these particles, they’ll definitely affect you, especially if you also have pets in the home. You and members of your family may develop chronic allergies as you breathe this dirty air. These particles can aggravate asthmatic conditions in those who suffer from them and make pre-existing respiratory conditions worse.

During the summer, the evaporator coils on your unit may freeze. When you try to cool your home, and cold air isn’t being dissipated efficiently, the condensation generated by the cooling process may turn into ice. When this happens, not only can it become impossible to cool your home, but your HVAC unit could even break down.

What Kind of Damage Can a Clogged Air Filter Do to a Furnace?

Perhaps the most significant damage a clogged air filter can do to your home is the havoc it wreaks on your furnace. A dirty filter can prevent your furnace from heating your home. Similar to what happens to your HVAC unit in the summer, a furnace that cannot dissipate heat efficiently grows hotter and hotter. Furnaces do have what’s known as a limit switch, which will automatically shut off your furnace when it reaches a specific temperature.

Usually, the limit switch will reset when the furnace temperature eventually drops. However, you’ll be unable to heat your home until your filter is replaced. Moreover, the high heat can cause damage to your furnace’s internal components, such as the fan, gas valves, heat exchanger, pilot light, pressure switches, or other parts.

Such damage can cause other problems. For example, a cracked heat exchanger could increase the carbon monoxide (CO) being produced, which could flow through the home. Given that CO is colorless, odorless, and potentially lethal, you’ll want to get your heat exchanger replaced if damaged.

In certain extreme cases, dirty filters may even trigger a fire. All limit switches will start to malfunction over time, but the likelihood that they will fail increases if continually triggered by an inefficiently-working furnace. Growing heat could very well result in a fire or even explode. Your filter might get sucked into your overtaxed furnace, greatly increasing the chances of a fire or an explosion.

What Should You Do If Your Furnace Stops Working?

Mechanical damage to your furnace from a dirty air filter is entirely avoidable. However, fixing broken furnace components is unavoidable and can cost you hundreds or even thousands of dollars. Depending on the extent of the damage, you may even need to replace your furnace.

The best way to deal with furnace damage is to prevent it from happening in the first place. Replace your air filter in your furnace and HVAC unit at least once every six months, or according to your manufacturer’s guidelines. Change it more frequently if you have children, pets, or otherwise create lots of debris.

Also, clean the ducts of dust and debris regularly, and ensure that the surrounding areas near both the ducts and the furnace are kept clear and uncluttered. If you don’t feel comfortable or don’t have the time to do this, make sure to schedule regular maintenance service to your furnace and HVAC system, including filter replacements from a certified HVAC technician.

Sometimes, a furnace’s mechanical failures will result in a failure to start. If you suspect your furnace is malfunctioning because you’ve neglected to change the air filter, first check the shutoff switch and breakers to make sure your furnace is, in fact, turned on. Check the gas line and pilot light, as well. Your gas line may have inadvertently been turned off, or your pilot light may not be lit. If you have a high-efficiency furnace, check the drain hose to see if sediment build-up or mold may be restricting it. If so, remove the hose and clean it with a small amount of bleach mixed with water.

If your furnace does, in fact, come on, but your rooms are not heating up evenly, check the ducts in the cold rooms to make sure they are open and unobstructed. Also, check any outside vents to make sure they are not clogged as well.

When Should You Contact a Furnace Repair Expert?

If you’re still suffering from a malfunctioning furnace, you’ll want to contract the services of a furnace repair expert to:

  • Further inspect your ventilation system to identify and remediate any hard-to-reach clogs
  • Check your heat exchanger, belts, blower motor, and flame sensor for damage and replace them if necessary
  • Assess your blower and clean it
  • Review all electrical connections and repair any identified faulty wiring
  • Recalibrate the thermostat if necessary
  • Inspect and test all safety controls, as well as the burner, pilot, and pressure

A well-trained technician should be able to quickly diagnose whether any furnace damage you are suffering indeed resulted from a clogged air filter, as well as pinpoint the exact nature of the damage.

Unfortunately, many HVAC and furnace repair experts charge you for this diagnosis, which is why you may be tempted to try to fix a serious problem yourself. But if you don’t know what you’re doing, you could inadvertently increase your risk of further damaging your furnace, voiding your warranty, CO leaks, and even fire.

At Aquarius Home Services, we don’t charge you to figure out what’s wrong with your furnace. Our expert technicians are available 24/7 to help you quickly determine and fix your malfunctioning furnace to make sure your home is heated. Servicing and repairing furnaces the Minneapolis & St. Paul Twin Cities metro area, Brainerd, MN, Baxter, MN, Mora, MN, Alexandria, MN and Siren, WI, we offer furnace maintenance service and emergency repairs that will restore your heat the same day you call us.

No matter the reason, if your heat has gone out, contact us today.

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