Key Takeaway
Turning on the heat for the first time often causes a smell. Yes, getting a whiff of burning dust is perfectly normal, but if it reeks like mold or burning plastic, it may need attention from a professional. However, if it gives off a sulfuric odor, that’s considered an emergency. Find out why these different smells happen and what you should do.
When you turn on the heat for the first time each year, you may notice a slight burning odor. This HVAC smell is normal, but other odors from your furnace may not be. Smelling mold, burning plastic, or sulfur, though, may require attention (and a sulfur smell is an emergency).
Why Does Your HVAC Smell of Burning Dust?
A faint scent of burning dust when you turn your HVAC on for the first time is completely normal. It should clear out quickly if you leave the heat running. Changing your filter before turning the heat on can help.
This odor is simply dust that’s settled in the system over the summer burning off. Leaving the heat running at a low level and building it up should reduce the smell. Consider turning your heat on for the first time when you won’t be home if you find it really annoying. The cleaner you keep your system, the less you will experience these odors. Make sure to change filters on the manufacturer’s schedule, and consider changing them more often if you have furry pets and/or indoor allergies.
Why Does Your Heating Reek of Plastic?
A slight burning plastic smell is normal with a brand-new furnace or heat pump. It’s caused by new components off-gassing and should clear up within a few days. You may also notice this after significant repairs. If it doesn’t dissipate quickly, though, you should call to get your installation checked.
If your furnace is not new, then a burning plastic odor may indicate that something in your system is overheating. It could also be caused by a foreign object (such as a child’s or pet’s toy) in the ductwork or on the floor vents. Remove any toys from the vents, and call for service if it persists.
Why Does Your HVAC Have a Moldy Odor?
A moldy or musty HVAC smell is most likely to be mold. This can be caused by a dirty air filter or dirty coils. It’s a good idea to get your coils cleaned twice a year, in spring and fall. Mold can make allergies and asthma worse and impact pets, so getting it cleaned out is important. Always replace the air filter if your heat (or air) has a musty odor.
If you can’t get rid of the odor, you probably need a technician to come give your system a good clean. Don’t leave it because mold can cause health problems for people and pets, especially if they already have health challenges related to allergies or their lungs.
Why Is a Sulfur Smell an Emergency?
Any scent of rotten eggs or sulfur in your home is an emergency. What you’re smelling is actually mercaptan, which is added to natural gas because methane, on its own, is odorless. If you notice a sulfuric odor when you turn your furnace on for the first time, turn it back off, evacuate everyone, and call your gas company’s emergency line. Don’t hesitate.
Keep Any Funky Smells From Coming Back
Back to that burning dust smell. Yes, it’s normal. However, there are ways to make it less obvious, such as changing air filters and keeping your system regularly maintained. Scheduling an inspection and maintenance check before you turn your heat on for the first time can help reduce odors and spot other problems before they become serious. Contact Smith & Keene to schedule your fall inspection today.
