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Can a Dirty Filter Stop a Furnace From Working?

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can a dirty filter stop a furnace from working

Is your furnace failing to heat your home? Let the specialists at Casper Friendly Services restore your comfort. Call today to schedule service! 

As a New Jersey homeowner, you rely on your heating system to keep you warm throughout the cold winter months. If your furnace stops working, the first thing experts often suggest is replacing your HVAC air filter. How can a dirty filter stop a furnace from working?

The experienced technicians at Casper Friendly Services explain this common issue in this in-depth guide. Learn from the team that provides the most trusted HVAC services in Jackson, NJ, and use this information to keep your furnace in good condition. By maintaining air filters, you can avoid damage to furnaces. 

What Is an HVAC Air Filter and How Does It Work?

The main purpose of your home’s HVAC filter is to trap dust and dirt particles that flow from your furnace or air conditioner. Every time your heating or cooling system runs, these particles, plus other allergens inside your home, can end up inside the HVAC system. Without a filter to catch the debris, the allergens will distribute to all areas of your house via your ducts and vents. 

Filters improve your indoor air quality by removing a number of harmful allergens from the air, including:

  • Dust
  • Pet hair and dander
  • Smoke
  • Lint

It’s up to you to keep your air filter clean. Otherwise, you’ll be left with poor indoor air quality and a malfunctioning furnace. 

How Can a Dirty Filter Stop a Furnace From Working?

Why do HVAC technicians recommend changing your air filter if your furnace starts experiencing issues? Filters can capture a lot of dirt and dust, especially if you run your heating system frequently. Over time, dirty air filters will start to impact the heater’s function and even shut off completely. 

Learn how this issue can cause your furnace to quit working. 

Dirty Filters Restrict Airflow

If you turn your furnace on and place a hand over a heating vent, you should feel a stream of warm air coming from the vent. This is only possible when you don’t have a clogged air filter. The allergens and dirt that collect in the filter will slowly restrict airflow, resulting in minimal heat traveling through your vents. 

Not only will this keep your house cooler than you’d like, but it also impacts the energy efficiency of your furnace. Government reports find that operating HVAC systems account for half of a household’s total energy usage. Your furnace will need to work harder to push air past the dirty filter and cause your utility bills to skyrocket. 

The Clogged Filter Will Trip the High-Limit Switch

If minimal heat comes from your vents, it’s a good indicator that you have a dirty filter. If the furnace quickly stops working after you turn it on, a clogged filter may be to blame. How can a dirty filter stop a furnace from working?

One of the most important safety features in a furnace is the high-limit switch. The main purpose of this switch is to prevent your furnace from overheating. It will automatically trip and shut off the furnace if it detects the temperature is too high inside the heater. 

While it’s good that your furnace won’t overheat, you need the high-limit switch to stay on in order to heat your home properly. Clogged filters won’t let any heat pass through and leave it inside the furnace. This ultimately trips the switch and shuts off the heater so it can cool down. 

Dangers of Not Replacing Your Air Filter

Changing your HVAC filter is necessary if you want to keep your furnace in good condition and maintain a healthy household. Failing to do so can leave you dealing with some dangerous consequences. 

High-Limit Switch Failure

Not only can a dirty filter stop a furnace from working temporarily, but it can even cause enough damage to the furnace that replacement is the only solution. Your high-limit switch may continuously trip because of a clogged air filter, but eventually, it can malfunction. When this happens, the furnace will no longer be able to shut down when it gets too hot. 

You risk overheating the system, which causes permanent damage. You also run the risk of a furnace fire sparking and putting your entire household in harm’s way. Avoid this hazard entirely by keeping a clean air filter inside your HVAC system. 

Poor Indoor Air Quality

It’s not only the damage to your furnace that matters. Clogged air filters can also wreak havoc on your indoor air quality. Since the filter is already full of dirt and allergens, it can’t capture all of the other dust particles that flow throughout your heating system. 

Without a clean filter that can trap these particles, you’ll notice your home could have more dust inside and even experience the following allergy-like symptoms:

  • Sneezing
  • Coughing
  • Throat and eye irritation

How Often Should You Change Your Air Filter?

HVAC experts suggest replacing your air filter every two to three months to avoid furnace malfunctions and maintain your indoor air quality. However, you may need to adjust your replacement schedule to better fit your needs. 

Households that rarely use their furnace won’t see their filter fill with dirt as quickly as households that use the furnace on a regular basis. In addition, the house’s total occupants and their habits can impact how quickly a filter will clog. Homes with multiple people plus pets will find the filter gets dirty faster, as well as households with smokers. 

You can plan to change your air filter every three months and adjust your schedule as needed. If, at the three-month mark, there’s minimal dirt, you may leave it for longer.

If you notice the furnace isn’t producing heat or your air quality suffers, change the filter and take note of how long it’s been since you first placed it. Keep that schedule going forward to avoid future problems with your heating system and save money. Not only can a dirty filter stop a furnace from working, but it can cause your energy bills to skyrocket. 

Signs You Need To Change Your Air Filter

Since most people only replace their filters a handful of times per year, it can be difficult to remember when to change yours. Thankfully, you can start to pick up subtle signs that you’re due for a replacement filter. Take note of the following warning signs that you need to change your HVAC filter. 

Your Home Becomes Dusty

Are you finding more layers of dust throughout your home than usual? Is the excess dust causing you to sneeze or cough more? You can alleviate these problems by changing your HVAC air filter. 

More dust appearing inside the house means that the filter is no longer able to trap allergens and instead sends these particles back through your vents. Be mindful of how dusty your house gets, and use this as your sign to change your air filter. 

Your House Doesn’t Heat Properly

Don’t assume that poor air distribution from your vents means something’s wrong with your furnace. As we know, clogged air filters restrict airflow and can cause your house to be colder in some sections or take a while to warm up. You’ll notice the biggest discrepancy tends to be in areas closer to the heater versus rooms that are further away. 

If you find that your home doesn’t have sufficient heating throughout all rooms and notice a weaker airflow, head to your furnace and check the filter. Chances are it’s full of dust. Swap out the dirty filter for a new, clean one, and you’ll find the house will heat up faster with an even distribution of warm air. 

The Furnace Cycles On and Off 

Are you constantly hearing the hum of your furnace turning on, only for it to abruptly shut off moments later? This short cycling means that your home won’t be able to reach your desired temperature since the furnace can’t run long enough to produce sufficient heat. As a result, you’re left with a chill in the air and potential damage to your furnace.

Don’t let short cycling go on for too long. The system can overheat and cause internal components to sustain serious damage. Changing the filter when this happens helps keep your heater running efficiently and prevents long-term damage.

Let Casper Friendly Services Inspect and Repair Your Furnace

After reading this guide, you no longer have to wonder, “How can a dirty filter stop a furnace from working?” If you want answers to other common questions to ask HVAC technicians, contact the experts at Casper Friendly Services. Our skilled technicians treat a variety of HVAC systems and work to make your home comfortable all year long. 

Give us a call whenever you experience issues with your furnace, and we’ll provide the solution for all your repair needs. Call us day or night at (732) 360-5334 to request immediate service. 

Author Bio:
Matt Casper

The Business Owner of Casper friendly services features a team of trusted HVAC contractors in Neptune, NJ. Local trustworthy business owner with 9 years experience! Honest, professional, and most of all affordable. Call Casper today to discuss your HVAC needs!