Burning Smell from Furnace: What Do You Need to Do?

A burning smell coming from your home’s gas HVAC system could mean there may be a problem with your heater, or the smell may be entirely normal. A furnace burning smell is common the first time you use the unit each season, but if you notice the smell of burning plastic, burning dust, or another electrical odor in your home throughout the winter, your furnace may be in need of repair.

Learn what burning smells coming from your furnace means and what you need to do if you notice such a smell. The professional, NATE-certified HVAC technician team of Williams Comfort Air is available around the clock to perform furnace repair when you need it most. If the burning odors are new, give us a call.

Is It Normal for a Furnace to Smell?

Odors that persist throughout heating season are not common from a furnace and typically mean there is a problem somewhere inside the system. However, a burning smell is quite normal coming from your HVAC system when you turn on your furnace for the first time each heating season.

Dusty Furnace Burning Dust Off

Over the down season, while your air conditioning is in use, dust can collect on components of the furnace, such as the heat exchanger and burners. When you turn on your furnace for the first time in the fall, you’ll likely notice the smell of burning, which is just the heating components burning dust off and not your furnace itself burning. This burning smell coming from your gas furnace should go away within an hour, though this burning dust does create noticeable odors in the home which can temporarily impact indoor air quality.

Rotten Egg Smell

If your furnace smells like rotten eggs, mold, or mildew can be indicative of a natural gas leak or mold growth within the heating and cooling system – these furnace smells are not normal and require immediate repair. If you notice a rotten eggs smell coming from the gas heat system, immediately turn off the system and get everyone out of the home first before you call 911 and your gas company. Inspection and repair need to be performed before you turn on and use the furnace again. Mold smells hamper indoor air quality and require professional services to eliminate the smell as well as kill mold growth within the furnace or air conditioning unit.

Carbon Monoxide Safety Tips

  • Have Your Fuel Burning Appliances Inspected Regularly by Professionals
  • Clean Your Fireslace’s Flue
  • Never Use a Generator Indoors
  • Run Your Kitchen Exhaust Fan When Cooking

Why Does My Furnace Smell like It’s Burning?

If you smell a burning smell at any other point throughout heating season, there could be a problem with your HVAC system. The burning dust smell coming from a heat system usually only happens with the first use of the season. When a smell of burning, whether it be dust or electrical burning, persists or happens mid-season, these odors are abnormal and repair could be necessary.

Common causes of a burning smell from a furnace unit include:

Dirty Furnace Filter

If you turn on your furnace for the first use of the season yet the smell of dust burning continues throughout the day, a dirty furnace filter is a common cause. When filters are clogged with dust and debris, smells from the furnace can linger in the home. When dust burns off furnace components, poor air movement through the system and filter can make your home smell like burnt dust for a longer period. Avoid air quality odor issues and other problems with your heat when you change the filter regularly as part of your heating system maintenance routine.

The furnace filter is often changed during a professional fall HVAC maintenance tune-up services, but it may be time for a new filter by the time you need heat in the home. Check the filter and replace it to make sure your heater has proper air flow in order to maintain good heating and air quality inside your home.

Overheated Blower Motor

Without adequate air flow, the furnace blower motor may overheat, making your home smell like something is burnt. This problem typically occurs due to poor air movement, stemming back to a dirty filter or blocked vents inside the home. When the motor overheats, the furnace may also shut down, which allows internal components like the heat exchanger to cool. If this occurs, check and change the furnace air filter and take a walk around your home to make sure all vents are open and unblocked.

When the blower motor overheats, internal components of the furnace can be damaged. Exposure to excessive heat can cause the heat exchanger to crack, which may cause carbon monoxide to leak inside your home. The limit switch is responsible to sense high heat temperatures and turn off the unit when they occur may become stuck and prevent the system from turning back on. If your filter is clean and vents are unblocked, call a professional for HVAC repair services to diagnose and fix the cause of this problem.

Melting Plastic Wire Casing

A home gas furnace has many electrical components and connections. When there is a problem with the wiring or electrical connections inside the furnace, you may notice a smell of burning plastic that makes its way into your home. Electrical burning smells and burning plastic odors need to be taken seriously – immediate repair services are necessary.

When electrical wiring burns off its insulation, electrical components within the furnace may sustain damage. Typically, these components of an HVAC system are checked and tightened during professional heating maintenance prior to heat season.

Need Heating Repair? Call Us Now

When a burning smell isn’t easily resolved by changing the filter and opening vents, service is needed to find the problem and correct it. Call Williams Comfort Air today to schedule professional heating repair service for your gas furnace system.

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