Most homeowners are used to their furnace emitting a burning smell the first time they turn it on this season. But what can you do if your heater constantly smells like that? While some furnace smells are completely normal, the smell of burning plastic, electrical odors, or burning dust can indicate deeper problems with your HVAC system.
Use this guide to find out what might be causing the burning smell when you turn on your furnace. Remember, at AC & Heating Experts Princeton, our team of NATE-certified professionals is always here to help.
How Should Normal Furnaces Smell?
Over the course of the year that your HVAC system is in operation, a fine layer of dust can accumulate in the heat exchanger, ducts, and ignition system. When your furnace is turned on for the first time each season, you may smell a distinctive burning odor as the dust in your system burns. This smell can be unpleasant, but should not last longer than an hour or significantly affect indoor air quality. If you’re worried about the smell, you can open a window slightly to ventilate your home until it goes away, or turn on a fan in the bathroom.
However, other smells can also be warning signs. Natural gas is artificially flavored and smells like rotten eggs. If you smell it, there could be a leak in your system. Turn off your gas and call 911 or your utility company. Mold can also indicate problems in your furnace, as there may be moisture issues that can lead to mold growth in your ducts.
What Else Can Cause a Burning Smell?
While the smell of burning dust once a season isn’t necessarily a problem, persistent burning smells could be a sign of a deeper problem. When something in your system is physically burning, it can create a persistent or intermittent burning smell that can recur throughout the winter.
Here are some common causes of furnace burning smells:
Grimy Furnace Filter
Furnace filters are like a gate through which air enters your system. Because filters trap fine particles like dust, pet hair, and air pollutants, your filter can become clogged. When filters fill with debris, dust and debris can circulate through your system and create a bad smell. Additionally, when dust burns through your system early in the season, the dirty filter traps certain odor molecules in your furnace, creating a lingering odor.
Air filters should be checked regularly and replaced as soon as they become dirty. Keep extra air filters on hand for quick and easy replacement, and perhaps set an alarm on your phone to check the air filters every few weeks. Replacing air filters when they become dirty is essential preventive maintenance on your furnace and can help extend its life.
Overworked Blower Motor
Any time your furnace filter is dirty or your vent lines are clogged, your furnace is at a higher risk of overheating. Poor air circulation can also be caused by clogged return air ducts, which can prevent cold air from circulating through the system. When this happens, heat can become trapped in the furnace, causing components such as the heat exchanger and blower motor to overheat. furnaces that overheat may shut down because the units have internal limit switches that trip to protect internal components. When furnaces overheat, the system can produce a burning smell. Ultimately, so much heat can build up in the system over and over again that the heat exchanger breaks and carbon monoxide can enter your home.
If your furnace is overheating, check the air filter and replace it if it appears dirty. Make sure all vents in your home are open and clear and that the thermostat is set to an appropriate heat level. If the filters are clean and your vents are in good condition and open, it may be necessary to call an HVAC professional to troubleshoot your system.
Wires Burning
Burning plastic smell may indicate a problem with the electrical connections in your HVAC system. Any time a cable’s insulation is damaged due to physical trauma, incorrect tension, or misplacement, a fault can occur that blows the protective insulation. In this case, the wiring can even start a house fire. If you smell the smell of burning electricity, take the problem seriously and contact an HVAC technician for immediate diagnosis and repair. Damaged cables can be checked, replaced or simply tightened. Electrical problems are a good reason to always have your furnace and HVAC equipment inspected and tuned up at the beginning of the season.
FAQs on What to Do If Your Furnace Creates a Burning Smell
Q: What should I do if my furnace creates a burning smell?
A: If your furnace creates a burning smell, it is important to take action immediately. This could be a sign of a serious problem, such as a gas leak or a fire hazard.
Here are some steps you can take:
- Turn off your furnace and pilot light. This will stop the gas from flowing to the furnace and reduce the risk of fire.
- Open the windows and doors to ventilate your home. This will help to remove any fumes from the air.
- Call a qualified HVAC technician to inspect your furnace. They will be able to diagnose the problem and make the necessary repairs.
Q: What are some possible causes of a burning smell coming from my furnace?
A: Some possible causes of a burning smell coming from your furnace include:
- Gas leak: A gas leak can be caused by a damaged gas line or a faulty valve. If you smell gas, it is important to evacuate your home immediately and call the gas company.
- Dirty or clogged air filter: A dirty or clogged air filter can restrict airflow and cause the furnace to overheat. This can create a burning smell.
- Overheating: If the furnace is overheating, it can create a burning smell. This can be caused by a number of factors, such as a dirty or clogged air filter, a problem with the thermostat, or a malfunctioning fan.
- Electrical problem: An electrical problem can also cause the furnace to overheat and create a burning smell.
Q: What are some safety tips I should follow to prevent a furnace fire?
A: Here are some safety tips you should follow to prevent a furnace fire:
- Keep your furnace clean and well-maintained. Have your furnace inspected and serviced regularly by a qualified HVAC technician.
- Change your furnace air filter every 1-3 months, or more often if you have pets or allergies.
- Keep flammable materials away from your furnace.
- Never leave your furnace unattended while it is running.
- Install a carbon monoxide detector in your home. Carbon monoxide is a colorless, odorless gas that can be fatal if inhaled.
Q: What should I do if my furnace catches fire?
A: If your furnace catches fire, it is important to evacuate your home immediately and call the fire department.
Here are some additional tips:
- Do not try to put out the fire yourself.
- Close all doors and windows behind you as you leave your home.
- Stay a safe distance from the fire and wait for the fire department to arrive.
Anytime You Need Heating Repair, Call Heating Experts in Princeton, NJ!
If your furnace stinks, give us a call here at AC & Heating Experts Princeton. In addition to diagnosing the cause of bad odors coming from your furnace, our HVAC technicians can optimize your gas furnace and help you keep your system in top condition. We are always available. So let us know if you need furnace repair.