Why Does My Furnace Smell Like Burning: Essential Guide!

Common Causes of Burning Smells in Furnaces

To identify the common causes of burning smells in your furnace and keep your indoor air quality in check, you need to understand the various factors behind it. 

In this section, I will walk you through the five sub-sections, Electrical Components, Overheated Blower Motor, Clogged Filter, Overheating of Internal Components, and Gas Leak, that can cause burning smells in your furnace. 

By knowing these common causes, you can either fix these issues yourself or call an HVAC specialist.

Electrical Components

Electric Components are important for furnaces. Let’s take a closer look at their behavior in the Table below.

CapacitorsInside or Outside FurnacePower surges can damage them.
Circuit BoardsIn Furnace and Thermostat LikewiseOverloaded circuits can cause burning out.

Capacitors can get damaged from power surges. Circuit Boards may also burn out if overloaded circuits occur. Other components, such as fan relay switches, may cause furnace’s burning smell.

It’s important to note that electrical malfunctions are responsible for one fourth of all house fires in the US annually.

If your furnace’s blower motor is like the sun, it’s trying to be the hottest thing in the solar system.

Overheated Blower Motor

A burning smell from furnaces is often a sign that the blower motor is overheating. This may be due to a buildup of dirt on the motor or a faulty capacitor. Dirt and debris can cause the motor to strain and overheat, creating an unpleasant smell. A failing capacitor could also cause the motor to slow down or stop, resulting in the same issue.

Preventing an overheated blower motor requires regular maintenance. Cleaning, lubricating, and checking for wear and damage can help. Replacing an old capacitor is also a good idea.

If you detect a burning smell, take action right away. Clean and maintain the motor to see if it resolves the issue. If not, get an HVAC specialist to inspect and repair the furnace. Don’t let a dirty filter turn your furnace into a smokestack, change it regularly.

Clogged Filter

A clogged air filter can cause major problems for your furnace.

  • Blocked airflow makes the furnace inefficient.
  • Safety switches activate, causing the furnace to shut down.
  • Overheating and hardware damage can result from filth buildup.
  • High energy costs are incurred when the furnace works harder than it should.
  • Allergens can accumulate if the filter isn’t changed every one to three months.

Without regular maintenance, your furnace could be in big trouble.

Overheating of Internal Components

When a furnace is too hot, it can cause problems. This could even be a fire hazard, so check it out right away. Usually, this is because of a blocked air filter or an issue with the blower motor. This means not enough air is going through, causing heat and bad smells.

If it’s not taken care of, the heat exchanger can be damaged. This lets carbon monoxide into your home. Plus, if you don’t clean your furnace, dirt can block the ventilation and cooling, and create oil residue on the walls that smells burnt.

Installation or DIY repairs can also be wrong, causing parts to get too hot. This can break pipes and cause gas leaks.

To avoid any major harm, get a certified technician to look at it. And if you smell gas, don’t light a match.

Gas Leak

A pungent, rotten egg odor may be a sign of a gas leak from your furnace. This is because gas leaks typically occur in the heat exchanger. If not taken care of, it could lead to dangerous outcomes, such as house fires or carbon monoxide poisoning.

Be aware of any signals of a gas leak. It might be due to corroded pipes, broken seals, inadequate ventilation, or an old furnace. To avoid these problems and keep your family safe, have a professional technician do routine maintenance.

Gas-leaks can be hazardous. They can spread in the air and lead to health issues, or worse, fire accidents. If you think there’s a leaky furnace, turn it off right away. Don’t wait, it could cause explosions or power outages. Safeguard your loved ones, don’t delay taking action against gas leaks.

why does my furnace smell like burning
Image of a furnace

Risks Associated with Burning Smells in Furnaces

To identify the risks associated with burning smells in your furnace, my solution is to discuss the potential dangers of such smells. These risks include a safety hazard, carbon monoxide poisoning, and fire risk. Each sub-section will highlight the dangers of these risks and emphasize the importance of taking immediate action in case of any burning smells.

Safety Hazard

The pungent smell from furnaces can be a safety hazard. Inhaling fumes may cause respiratory issues, headaches, nausea, and dizziness. And as the furnace heats up, it can become flammable. Any spark or ignition could cause an explosion. It’s even worse if the device hasn’t been maintained.

Carbon monoxide is particularly dangerous. It’s colorless and odorless, so it’s hard to detect. In extreme cases, a gas leak can even be deadly.

To prevent risks associated with unsafe heating systems, an annual check-up by a professional is essential. Inspect the furnace for cracks, corrosion, air ducts cleanliness, and the condition of filters. If an unusual smell occurs, shut the system down. Ignoring warning signs could be disastrous.

If there’s a gas leak or the carbon monoxide alarm goes off, leave the house and call emergency services. Not doing so could lead to fatal accidents or permanent harm. Regular maintenance and awareness about potential threats can help protect life and property in case of an emergency.

Carbon Monoxide Poisoning

Furnaces that smell of burning can be hazardous. The ‘silent killer’, carbon monoxide, is a colourless, odourless and tasteless gas. It is difficult to detect without the right equipment and training.

If furnaces are not looked after or are faulty, they release carbon monoxide, which causes headaches, dizziness, weakness, nausea and vomiting, like seasonal flu symptoms. Left untreated, it can be fatal.

Carbon monoxide poisoning is a risk for all ages, infants, elderly people and those with existing medical conditions.

In America, 400 people die annually from unintentional carbon monoxide poisoning due to damaged heating equipment. Additionally, in England and Wales in 2013-14, over 4,000 people were hospitalised from exposure to the gas. Those aged 60 and over had the highest rate of hospital admissions per 100,000 people (5.5%).

Fire Risk

Burning smells coming from a furnace? That’s a warning sign. Fire hazard, toxic fumes, and potential property damage could all result if left unchecked. So, pay attention to any burning smells and address them immediately.

Routine maintenance will help stave off potential problems, but accidents can still happen. A friend of mine experienced a close call when their furnace emitted strong burning smells. Fortunately, they contacted a technician in time. Corrosion on some components was the cause. 

Burning smells from your furnace must be taken seriously. Not only because of fire danger, but also toxic fumes and faulty ventilation systems. Routine maintenance is key, but don’t hesitate to get professional help if you notice a problem.

Signs You Need Furnace Repair

To determine if you need furnace repair, identify the signs your system’s exhibiting. If you notice any Unusual Smells, Poor Air Movement, Unusual Noises, or the HVAC system not turning on, it might be time to call in an HVAC professional. 

Unusual Smells

Strange smells from your furnace could signal a problem. Like rotten eggs, which often mean natural gas is leaking. Or burning and musty smells. You need professional help straight away. Otherwise, the situation might worsen and be costly. Plus, ignoring such smells can lead to fatal carbon monoxide poisoning.

So, get your furnace checked regularly by qualified technicians. Don’t forget that heating equipment caused 15% of reported house fires between 2014-2018. If your home air feels stagnant, don’t light scented candles, call for furnace repair.

Poor Air Movement

Insufficient airflow within the furnace system can cause several issues that require expert help. Chilly spots, unreliable temps, and even carbon monoxide poisoning may result from poor air circulation.

This could be caused by several factors, such as dirty filters, clogged ducts, damaged fan motors, and belts. Not just that, a clogged filter can also lead to unhealthy air circulation in your home. This can be especially dangerous for people with breathing difficulties.

Hence, if you recognize any signs of reduced airflow, don’t hesitate to call an HVAC specialist. Your furnace may be sending you warning signals, but if it’s screeching like a banshee, don’t ignore it. Get professional help straight away.

Unusual Noises

Unexpected Noise Coming from Furnace?

Hear strange noises coming from your furnace? This could indicate a problem. 

Sounds range from high to low pitch. Could be worn-out or malfunctioning components.

Screeching, squealing, grindingBlower motor issue
Rattling or bangingBroken or loosened item
Pops or crackingOverheating and metal expansion

Promptly contact an HVAC service. Early detection saves money & hassle. Don’t ignore unusual noises. Minor repair now avoids costly damage later.

Regular annual maintenance is key for furnace efficiency. Clean & change air filters, tighten connections, lubricate parts, check thermostat. Keep comfort levels up during cold season.

HVAC System Not Turning On

When your HVAC isn’t firing up, it’s a major inconvenience. 

Do this if your heating, ventilation and air conditioning isn’t working:

  1. Check the thermostat – Make sure it’s set right, and change any dead batteries.
  2. Inspect the air filter – Dirt can lead to poor airflow, making the system shut down or run bad.
  3. Examine the circuit breaker – Reset it if it’s been tripped. If it trips again, call an electrician.
  4. Verify the furnace switch – This is on the exterior wall beside the furnace. It should be set to “on.”
  5. Contact a pro – If you’ve done all this and your HVAC still won’t turn on, get an expert.

Delaying repairs can lead to higher costs in replacements and emergency services. The Global Market for Heating Equipment is estimated to pass $50 billion by 2026. Don’t be left in the cold, maintain your HVAC.

Importance of HVAC Maintenance

To ensure that your HVAC system runs efficiently and effectively, it is important to prioritize maintenance. 

Regular Filter Changes

Filter changes are a necessity when it comes to HVAC maintenance. Doing this regularly keeps the system in good condition and provides various advantages as

  • Dirty filters reduce air quality.
  • Clogged filters hike up energy bills.
  • New filters increase air flow and enhance the life of the system.
  • Regular filter changes stop breakdowns and pricey repairs.
  • Filters influence indoor comfort and productivity.

Neglecting filter changes can cause respiratory problems, allergies, or worse. It will also lead to dust and dirt buildup in the building.

Studies suggest regular filter changes enhance cognitive functioning and workplace satisfaction. Harvard’s School of Public Health conducted a study which revealed that improved air quality caused a 101% boost in cognitive scores for office workers.

Instead of trying DIYs, it’s best to hire an HVAC expert before your home turns into an oven or a fridge.

Hiring an HVAC Professional

Hiring a Professional HVAC Technician

Choosing the right HVAC pro is a must for your system’s efficiency and long life. An inexperienced tech may not spot underlying issues that will cost you more in repairs or replacements.

A skilled technician needs to be trained in the latest technology and equipment, and licensed, bonded, and insured. Also, they should show excellent customer service, coming on time, explaining the diagnosis clearly, and providing quotes before repairs start.

By choosing a professional HVAC technician, you can avoid unnecessary repairs and replacements. Plus, you get timely maintenance services that extend your system’s life.

A friend went with cheap HVAC service providers who charged low prices. Sadly, the contractor used poor parts despite red flags. This ended up costing him double what he’d pay if he’d called an experienced professional in the first place. Not maintaining your HVAC is like not going to the dentist, it may save you money, but the long-term effects are too bad.

Upfront Costs vs Long-Term Savings

Investing in regular HVAC maintenance brings significant long-term savings. This is shown in the table below. The first column covers upfront costs, such as installation fees, equipment costs and permits. The second column outlines long-term savings, including lower energy bills, fewer breakdowns and repairs, and improved equipment lifespan.

Upfront CostsLong-term Savings
Installation feesLower energy bills
Equipment costsFewer breakdowns and repairs
PermitsImproved equipment lifespan

Maintenance may seem a costly option at first, but it can be highly cost-effective in the long run. Plus, there are other benefits, such as improved indoor air quality and increased system efficiency.

The U.S. Department of Energy notes that households can save up to 20% on their heating and cooling costs just by properly maintaining their HVAC systems. Moreover, a study by Mechanical Systems Week reveals that not maintaining an HVAC system leads to a 5% deterioration of the system each year.

Steps to Take If You Smell a Burning Smell in Your Furnace

To address the problem of a burning smell from your furnace, follow these steps to ensure the safety of your home and HVAC system. Turn off your HVAC system, arrange for an HVAC specialist to check and repair your system, and check for gas leaks or carbon monoxide. It’s important not to attempt anything yourself to minimize the risk of further damage or safety hazards.

Turn Off Your HVAC System

When you smell a burn coming from your furnace, it’s important to stay safe and turn off your HVAC system. Here’s how:

  1. Locate your thermostat and switch it off. This will stop the flow of hot air.
  2. Go to your furnace and turn off the power supply close by.
  3. If you have a gas furnace, shut off the gas valve near the unit.
  4. Get a professional HVAC technician to inspect and repair anything wrong with your furnace before turning it back on.

Ignoring a burning smell can cause major damage or even a deadly fire. So, switch off the HVAC system right away when you detect burning odors from your furnace.

Remember that prevention is better than cure. Regular inspection and maintenance of your furnace can help avoid any dangerous situations. Don’t wait until it’s too late.

Call an HVAC specialist

If you smell burning from your furnace, it’s best to contact an HVAC expert. They can quickly find the source of the odor

Don’t try to fix it yourself, this could be dangerous. Get professional help from a skilled HVAC specialist.

The technician will investigate your furnace and determine why it smells. If needed, they can clean the unit to get rid of any excess buildup. They may also check the carbon monoxide levels and suggest solutions.

It’s wise to have your furnace checked at least once a year. An HVAC service agreement can help with this and save you money in the long run.

According to the NFPA, heating equipment is responsible for 15% of all home fires. Early detection of issues can reduce the risk of accidents. Before it gets too hot, check for gas leaks or carbon monoxide.

Check for Gas Leaks or Carbon Monoxide

Detecting abnormal odors in your furnace? It’s important to check for gas leaks or carbon monoxide (CO) right away. These gasses can cause respiratory issues or even be life-threatening. So, see if any hazardous gasses could be leaking and act fast.

Furnaces generate combustion-related waste, like CO. It can leak inside if the equipment isn’t working or has broken down. Consider buying a CO detector. It will alert you if dangerous levels are found.

People don’t always notice signs until they feel its effects. At first, it’ll be mild headaches and dizziness. Later, confusion, nausea and even death may occur. 

Suspect a gas leak or CO? Seek medical help immediately. To stay safe, pay attention to ventilation and maintenance too. Don’t try to repair your furnace without professional help.


1. What causes a burning smell coming from my furnace?

A burning smell from your furnace can be caused by a variety of factors, including dust accumulation, a clogged air filter, electrical issues, or a malfunctioning motor.

2. Is a burning smell from my furnace dangerous?

In most cases, a burning smell from your furnace is not dangerous. However, it is important to address the issue promptly to prevent any potential hazards or damage to your furnace.

3. How long does the burning smell last?

The duration of the burning smell can vary depending on the cause. It is recommended to monitor the smell and contact a professional if it persists for more than a few hours.

4. Should I turn off my furnace if I smell burning?

If you notice a burning smell coming from your furnace, it is advisable to turn off the furnace and contact a professional HVAC technician to inspect and diagnose the issue.

5. Can a dirty air filter cause a burning smell?

Yes, a dirty air filter can restrict airflow and cause the furnace to overheat, resulting in a burning smell. Regularly changing or cleaning your air filter can help prevent this issue.

6. Can a burning smell be caused by a gas leak?

While a burning smell is not typically associated with a gas leak, it is important to be cautious. If you suspect a gas leak, evacuate your home immediately and contact your gas provider.

7. How often should I clean my furnace to prevent a burning smell?

It is recommended to have your furnace professionally cleaned and inspected at least once a year to prevent dust buildup and potential burning smells.

8. Can a burning smell be a sign of a serious problem?

In some cases, a burning smell can indicate a serious problem with your furnace, such as a faulty motor or electrical issue. It is best to have a professional assess the situation to ensure safety.

9. What should I do if the burning smell persists after cleaning the furnace?

If the burning smell continues even after cleaning the furnace and changing the air filter, it is crucial to contact a professional HVAC technician to diagnose and resolve the issue.

10. Can a burning smell from the furnace affect indoor air quality?

Yes, a burning smell can indicate the presence of pollutants or contaminants in the air. It is important to address the issue promptly to maintain good indoor air quality.


It’s essential to call a pro when your furnace needs repairs. DIYing can be risky and result in more damage. A licensed technician has the right training, knowledge and tools to diagnose and fix furnace issues safely. DIYing may cause electric shocks or gas leaks, which can lead to injury or even death. Other repairs can be costly if you make them worse. So, if you smell burning, phone a professional straight away. Also, fixing the furnace yourself may make any warranties or insurance void. The technician can document their work properly, so any repairs are covered. Regular maintenance and inspections by a pro can save time and money in future, by preventing potential issues.