4 Reasons Why Your HVAC’s Air Filter is Dirty: Our Guide

The colder months are coming, meaning you and your family are going to be turning up your heating. Unfortunately, you may not be able to do so effectively when your HVAC has dirty air filters, which can affect its energy efficiency, temperature control, and air quality. But don’t worry. We will help you determine what’s causing your HVAC filters to turn black. All you have to do is keep reading to find out! 

This article will discuss the four common offenders to having pitch-black, contaminated air filters in your household’s HVAC system. Take this as an opportunity to preserve your family’s convenient access to heating and cooling. That way, you can have a truly comfortable, efficient home! 

Lighting certain candles 

During the festive season, you and your family may love to light scented candles to get into the holiday spirit. You have to be careful, though, because many candle variants don’t burn properly, which can produce harmful soot that can latch onto your HVAC’s air filters. You and your family may get sick as you inhale toxic soot particles. 

As such, test your candles first when you buy them and don’t forget to read the product description. One good indicator that your candle may be producing harmful soot is by checking on its flame. Ideally, you want a blue frame, indicating a soot-free, safe burn. 

You can also check the candles’ list of ingredients for soot producers like petroleum jelly and vegetable oil. Consult with HVAC maintenance experts to help you make well-informed candle purchases.  

Having a dirty home 

Your household may not use your HVAC properly because of the many air contaminants around your surroundings directly affecting the air filter’s quality and effectiveness. That’s why you need to clean your house regularly and vacuum all the hard-to-reach areas to mitigate dirt accumulation. 

Not replacing your air filters 

Don’t leave your HVAC running when you haven’t replaced the air filters in a long time, especially when you can tell there are changes in your household’s quality of air and your electricity consumption. 

For instance, you may notice big changes in your HVAC’s heating capacity because you have to turn up the thermostat but didn’t have to before. Often, you will find your HVAC’s air filters to be extremely dirty. 

The best way to practice self-HVAC maintenance is to replace your air filters. Read your HVAC’s product manual or consult with contractors. That way, you can avoid costly repairs and other inconveniences that prevent your household’s access to timely temperature control! 

Having a water heater or gas furnace 

Unfortunately, some water heaters and gas furnaces may be producing soot that can affect your HVAC, leading the air filters to become black. The key contributing factors to soot production are improper gas burning, a malfunctioning heat exchanger, and clogged burners. 

As such, consult with our experienced furnace maintenance experts to help you correct the issue. Having your water heater and gas furnace serviced ensures your HVAC’s efficiency! We can also provide you with state-of-the-art furnaces for your convenient replacement. 


Having contaminated air filters can be a nuisance to deal with, especially at home. Fortunately, you now have a better understanding of what causes it. All you have to do is adhere to the proper guidelines and seek other solutions to maintain your HVAC. Remember all the previously mentioned tips and sustain your household’s timely access to effective temperature control! 

Are you looking for professional heating and air conditioning services in Edmonton? We at Legacy Heating can provide you with that. We can help you ensure you have access to clean, efficient temperature control solutions. Have your air filters cleaned and maintained with us today! 

HVAC Brands We're Proud to Carry

Legacy only uses the most efficient and cost-effective HVAC products. We pride ourselves on putting quality and customers first! We will equip your new home with the best HVAC system and offer the most reliable residential heating service in Edmonton and Calgary.

Contact Us Today

We’ll help you find the right heating and air conditioning system for you and your budget.

Edmonton Area 780-733-1256 Calgary Area 403-451-1337

Honesty, Integrity, Legacy