Can Furnaces Catch Fire?

The return of cooler temperatures raises your reliance on home heating equipment every fall. If your furnace isn’t working properly, it could develop into a fire hazard and jeopardize your family’s safety. 

As reported by the National Fire Protection Association (NFPA), heating systems like furnaces are a major factor of home fires, contributing to almost 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage each year. Space heaters and fireplaces cause most of the fires concerning heating equipment, but central heaters, including furnaces, are responsible for just about 12% of these blazes. Learn the most likely causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Aging furnaces are more exposed to safety problems since they might be manufactured differently and slide into disrepair over the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should be aware of these causes of furnace fires. 

Overheating Motor

A furnace motor can overheat in various ways. Here are the biggest risks:  

  • A clogged filter can impede airflow and force the motor to work longer. At some point, the motor may overheat, elevating the risk of fire. 
  • Dirt can accumulate around and coat the motor, forcing it to absorb heat, which can cause a fire. 
  • Exposed or corroded wiring can cause the voltage to get too high, increasing the risk of an electrical fire. 
  • Excessively tight or damaged motor bearings can heat up whenever the furnace is on. Without adequate lubrication, the bearings could eventually catch fire. 

Clogged Furnace Flue 

Yard waste, animal nests and other materials can block the furnace flue, reducing oxygen. This leads to soot building up and improper ventilation, limiting efficiency and increasing the risk of flame rollout. Flame rollout is when fire gets out of the heat exchanger and burns the parts in your furnace. If this problem persists, your heating equipment can be severely damaged, and the fire could spread to areas outside the furnace. 

Obstructed Heat Exchanger 

The heat exchanger is a restricted combustion chamber where the heat created by your furnace is moved to the air circulating throughout your home. A heat exchanger clogged with soot or corrosion has the same impact as a blocked furnace flue—reduced performance and a higher risk of flame rollout. 

Cracked Heat Exchanger 

Various problems occur if corrosion damages the heat exchanger. First, it reduces suction in this chamber, leading to less airflow and increased flame rollout. Second, it releases fumes, including carbon monoxide, into your home. Breathing in CO gas can be deadly, so never dismiss your carbon monoxide alarms. CO gas can also return to the source of the leak and ignite if a flame is present. 

Improper Gas Pressure 

Furnaces need an accurate mixture of natural gas and air to ensure safe and efficient combustion. Too little pressure is often the result of clogged burner orifices. This problem makes the burner flames more likely to roll out. It also causes unwanted condensation in the heat exchanger, increasing the rate of corrosion. 

On the other hand, high gas pressure can lead to excessive heat in the furnace, which can cause the soot inside the heat exchanger to ignite. Such fires can quickly spread to other areas. 

How to Prevent Furnace Fires 

Based on the listed ways a furnace can catch fire, here are the steps you can take to prevent furnace fires: 

  • Change the air filter regularly: Check the filter each month and change it when it seems dirty or every three months, whichever comes first. 
  • Keep an eye on the furnace flue: Inspect the exterior vent for obstructions and remove any you find. 
  • Don’t store combustible items close to the furnace: Things including cardboard boxes, paper, clothing and other combustibles should be kept at a minimum 3 feet away from the furnace and any other heating equipment. 
  • Add a flame rollout switch: This safety system detects if a fire or hot exhaust gases are inside your furnace’s burner compartment. If the rollout switch triggers, have your furnace inspected as soon as possible to diagnose and repair the problem before it results in a furnace fire. 
  • Schedule annual furnace maintenance: It isn’t always easy to recognize if your furnace is performing unsafely. Whether you notice warning signs or not, prioritize furnace maintenance every fall. 

Schedule Furnace Services Today 

Is it time for your yearly tune-up? Do you need help resolving a problem with your furnace? Whatever the case, Service Experts Heating, Air Conditioning & Plumbing is here for you. Our HVAC professionals can inspect, clean and test the system to ensure safe operation. If anything looks out of place, we’ll perform a repair or a modification, giving you peace of mind that your furnace is unlikely to catch fire. For more details or to schedule furnace maintenance, please contact your local Service Experts Heating, Air Conditioning & Plumbing office today. 

  • Eight Common Heating Myths Debunked

    There are plenty of myths out there about home heating that cause confusion and inefficient furnace operation. It’s time to get the facts out there. Here, the heating authorities at Service Experts Heating, Air Conditioning & Plumbing reveal the truth behind the eight most common myths to keep... Continue reading

  • How to Choose a Suitable HVAC System

    When it comes to keeping your home comfortable year-round, nothing is more essential than picking out the right heating, ventilation and air conditioning (HVAC) system. This decision affects your daily comfort, monthly utility bills and overall home efficiency. Then again, with so many system... Continue reading

  • Year-End HVAC Maintenance Checklist

    Now that the air turns chilly, you know it’s time to get your home ready for the cooler months ahead. Your heating system is critical to maintaining a cozy, warm setting. A well-maintained furnace supplies the comfort you want while using a smaller amount of energy. Regular inspections also make... Continue reading