Furnace Safety: Tips to Avoid Furnace Dangers

It’s that time of year again — the holidays are coming up, and with that means chilly temps and winter weather on their way if they haven’t already arrived. Pretty soon, you’re using your furnace throughout the day as well instead of just at night, and it’s going to be several more months before you shut it completely off again.

In order to enhance furnace safety and prevent furnace dangers during long-term use, it’s important to service your furnace regularly and pay attention to any strange, suspicious, or faulty sounds or functions. Fortunately, it’s pretty simple to keep on top of furnace maintenance and provide routine repairs to keep it running at its best. A few of these you can perform at home, while others you should leave to a professional.

Basic Gas Furnace Safety Tips

When you adjust the thermostat on your gas furnace, an ignitor activates the gas burners that create heat in a combustion chamber. This warm air is then distributed through the ductwork by blowers and thus heats your house. Gas furnaces are great if you’d like a more cost-efficient and even heating system, but also come with their own set of unique safety issues. Here’s a list of ways to keep your gas furnace functioning safely, and when it might be best to contact a professional.

  • Schedule a furnace cleaning and check-up to be performed yearly (before winter starts) by a NATE-certified technician. Request that s/he checks for cracks in the combustion chamber, as these cracks could allow carbon monoxide to leak into your home.
  • Change the air filter regularly. Dust particles can build-up on the furnace’s air filter and reduce efficient airflow and heating capabilities, as well becoming a fire-hazard or furnace failure potential in extreme instances of neglect. The air filter is usually located inside the front cover of your furnace, and should be changed before the winter season starts, and at least once every 1-3 months during regular use.
  • Don’t close off more 20% of the furnace registers in your house. This can cause unnecessary heat build-up and affect the efficiency. Make sure to avoid obstructing registers as well, and keep them free of lint, dust, and pet hair by vacuuming them at least once a month.
  • Don’t store anything flammable or combustible near or around your furnace to avoid a furnace fire.
  • Keep the area around your furnace clean and unobstructed.
  • Install a carbon monoxide detector in your home, and check to make sure it’s working properly at least once a month during the winter season. Gas furnaces have a risk of carbon monoxide poisoning if they’re not functioning properly, but having a detector installed can help you stay on top of risks.
  • If your pilot light seems to go out often, make sure there aren’t any drafts preventing it from staying lit. If pilot light issues persist and it seems that the issues stem from the ignitor (or the pilot downright refuses to relight), call an expert.
  • If you detect a gas smell or suspect other gas feed or valve issues, call a professional.

Basic Electric Furnace Safety Tips

No combustion tanks here! When you activate your electric system’s thermostat, you’re also activating banks of coils in your furnace’s cabinet that burn hot when air is flowing through them. The higher you crank your heat, the higher the number of heating elements that turn on.

Electric furnaces are a great solution for homeowners who want a system that’s relatively easy to maintain and requires less upkeep than a gas furnace. There’s also little to no chance of carbon monoxide poisoning, but electric furnaces require a little more energy to run. Making sure your electric furnace is running safely entails similar upkeep to that of a gas furnace, and couldn’t be simpler.

  • Much like a gas furnace, it’s a good idea to have your electric furnace serviced and cleaned at the start of the cold weather season to make sure it’s still functioning well and will perform at capacity for the next few months. Make sure the person you contact is NATE-certified.
  • As with a gas furnace, the air filter needs to be changed regularly. Every 3-4 months is recommended to maximize heating efficiency and prevent overheating issues.
  • Mechanical problems could be caused by something as simple as the internal mechanisms needing to be oiled and cleaned, or it could be something more complicated. Call a professional to handle those issues.
  • Make sure the area around your furnace and any vents is kept clear and clean. Don’t store anything flammable or combustible near the furnace or any elements that distribute heat.
  • It’s a good idea to routinely perform a quick clean of the unit. Cleaning should involve cleaning/changing the filter; cleaning the air-blower, the motor housing, and any belts; and always disconnect from the power source before proceeding. Stick around to test the furnace function again before turning it back on and walking away or leaving the house for extended periods of time.

How often should a furnace be serviced?

Technician looking over a gas furnace with a flashlight before cleaning it.
You should have your heater serviced by a professional if it smells like gas, makes unusual noises, or emits a burning smell. Image source: DepositPhotos.com

Whether your heating system is a gas or electric furnace, it’s a good idea to make sure it’s running safely and efficiently before the winter season. A poorly-running furnace can actually be dangerous and pose some hazards to your home and family. There are a few common heating problems that you’ll need to watch out for as a furnace owner.

Common Furnace Problems

  • Dirty or Clogged Filters: This issue reduces airflow and makes the furnace work harder to heat. In addition, if left long enough, an especially dirty or clogged filter could cause damage to the limit switch, which controls the fan.
  • Pilot Control Issues: With a gas furnace, there can be issues with the pilot light, whether stemming from a faulty ignitor or thermocouple problems.
  • Furnace Won’t Heat At All: If your furnace is having issues expelling heat, there could be issues due to a faulty thermostat, the thermostat setting, power connection, gas connection, or pilot light.
  • Furnace Doesn’t Heat Enough: This could indicate a clogged filter or a unit that is too small for the space it’s being used to heat.
  • Frequent Cycling: If the furnace seems to be constantly cycling from “Off” to “On,” check for a clogged air filter, improper air flow, or a bad thermostat setting.
  • Blower Continuously Runs: This could indicate a faulty limit switch, and it’s recommended you have a professional look the unit over.
  • Furnace Is Especially Noisy: Squeaks and rattles aren’t normal to furnace models. These sounds would indicate a mechanical issue, airflow reduction, or a clogged burner.
  • Blank Thermostat Screen: If the furnace won’t work and the thermostat’s screen is blank, check the breaker for a blown or tripped fuse.
  • If Your Furnace Smells Like Gas: Your gas furnace should NEVER smell like gas. If you detect even the slightest fumes, shut it off and have a professional check it out as soon as possible.
  • Hot or Burning Smell: A burnt smell or an actively smoking heater indicates that something is NOT right. Shut off your furnace immediately and if it’s electric, unplug it. Have a professional check it out as soon as possible. A faint unpleasant smell could merely indicate a dirty air filter that needs to be changed or dust build-up within the furnace, which would be rectified by simply changing the filter or cleaning your unit.

Built-In Furnace Safety Features

Whether your home is heated with a gas or electric furnace, each furnace will come standard with a few safety features. These help protect your home from furnace fires, high energy bills, and constantly running a faulty furnace, but it’s still a good idea to have the furnace gone over and checked for mechanical issues at least once a year.

  • Furnace Safety Switch: The furnace safety switch, also known as the limit switch, measures the temperature of the heat outside the combustion chamber. When the switch detects flames or temps that are too high, this could mean a fire hazard. Once activated, the limit switch cuts off the furnace gas supply in order to keep potential flames from spreading and lowers the risk of carbon monoxide from leaking into your home. The furnace will need to be reset by a professional to be used again.
  • Thermocouple/Mercury Flame Sensor: Older furnace models are equipped with the former, while the latter comes with newer models. They both function much the same way – if the pilot light goes out or burns too weakly, the gas is automatically shut off to prevent leaks.
  • Air Pressure Switch: Newer furnaces are built with small fans (called draft inducers) that run after each heating cycle to remove excess gas from the combustion chamber. This fan is equipped with the air pressure switch that shuts off the gas supply if it detects too little air being blown by inducer.

Keeping your home warm and toasty during the winter months is very important, as is furnace safety. Feel free to perform some simple troubleshooting at home, but if there’s any gas or burning smell, be sure to contact a professional right away.

If you’re in the market for a new furnace, browse our gas and electric heaters to discover the best solution for your home. Need help deciding? Check out our top gas and electric heaters below:

Top Gas Heaters

Top Electric Heaters

Image of Goodman HKSC08XC 7.0 kW Heat Kit for Air Handlers
The Goodman HKSC08XC 7.0 kW Heat Kit for Air Handlers.

Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.


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