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What is the most common reason furnace stops working?

What Is The Most Common Reason Furnace Stops Working?

Warm and cozy homes are no less than a sanctuary during the harsh winter months. But what happens when your furnace, your main source of warmth, stops working? It can be frustrating and inconvenient, often leaving you in a chilly situation. As a leading provider of heating repair in Vacnouver, we often encounter this query from our clients – “What is the most common reason a furnace stops working?”

Understanding the potential reasons behind furnace failures is key to preventing such circumstances and ensuring consistent comfort in your home. This article aims to shed light on the common issues that may cause your furnace to stop operating, from lack of power and thermostat issues to problems with air flow, malfunctioning blower motors, and issues with the gas supply. By understanding these issues, you can take proactive steps to prevent them or know when to seek professional help.

So, let’s dive in and uncover the most common reasons behind furnace failures, helping you stay prepared and maintain a warm and comfortable home.

Why is the furnace not working?

There could be several reasons why your furnace is not working properly. Sometimes, the issue might be as simple as a tripped circuit breaker or a malfunctioning thermostat. In other cases, it could be a more complex problem, such as issues with the ignition or pilot light. To help you better understand these issues, we’ve broken down some of the most common reasons why a furnace might stop working:

  • Lack of power: This could be due to a tripped circuit breaker or a blown fuse. Always check your home’s electrical panel to see if the breaker has tripped or the fuse has blown. If this is the case, resetting the breaker or replacing the fuse might solve the problem.
  • Thermostat issues: If your furnace isn’t turning on or off as it should, the issue might lie with your thermostat. Check to see if the thermostat is set to “heat” and that the temperature setting is higher than the current room temperature. If the thermostat runs on batteries, check to see if they need replacing.
  • Ignition or pilot light problems: If your furnace has a pilot light, check to see if it has gone out and try relighting it following the manufacturer’s instructions. If your furnace has an electronic ignition, it may need to be reset. Alternatively, the ignition might be faulty and require professional help.

These are just a few potential reasons why your furnace might not be working. However, if you’re unable to identify or fix the issue yourself, it’s always best to call in a professional. At Sub Zero Temp Control, we offer expert heating repair to help get your furnace up and running again.

Lack of air flow

Another common reason why your furnace may stop working is due to a lack of air flow. This can often be caused by dirty or clogged air filters, blocked vents or ducts, or issues with the fan motor. When there’s insufficient air flow, your furnace may overheat and automatically shut down to prevent damage. Let’s delve into these issues more:

  • Dirty or clogged air filters: Over time, air filters can become clogged with dirt and debris, restricting the flow of air into your furnace. This not only causes your furnace to work harder but can also lead to overheating and automatic shut down. Regularly checking and replacing your air filters can help prevent this issue.
  • Blocked vents or ducts: Similarly, blocked vents or ducts can restrict air flow and cause your furnace to overheat. Make sure all vents and ducts in your home are clear and unblocked.
  • Fan motor issues: If the fan motor in your furnace is not working properly, it can lead to insufficient air flow. You might notice that the fan is not running or it’s making unusual noises. In such cases, professional heating repair services are required.

Ensuring proper air flow is crucial for the efficient operation of your furnace. Regular maintenance and inspections can help identify and address these issues, ensuring your furnace continues to keep your home warm and comfortable throughout the winter months.

Malfunctioning blower motor

Another common reason your furnace may stop working is due to a malfunctioning blower motor. This is a critical component of your furnace system as it circulates the warm air throughout your home. When the blower motor is not working as it should, it can lead to several issues including inadequate heating or even a complete system shutdown. Let’s explore some of the most common symptoms of a malfunctioning blower motor:

  • Blower motor not running: If your blower motor isn’t running, you may notice that your furnace starts but fails to distribute heat throughout your home. This could be due to a faulty motor, problems with the capacitor, or issues with the control board.
  • Blower motor making strange noises: Unusual noises such as humming, buzzing, or screeching could indicate a problem with the blower motor. It could be due to loose or damaged parts, or it might need lubrication.

If you notice any of these issues, it’s best to seek professional help. At Sub Zero Temp Control, our heating repair services include comprehensive inspections and repairs for blower motors. By addressing these issues promptly, you can ensure the efficient operation of your furnace and maintain a comfortable environment in your home.

Issues with the gas supply

Another common issue that could cause your furnace to stop working is problems with the gas supply. Remember, your furnace requires a consistent and adequate supply of gas to function effectively. However, several issues might interfere with this, ranging from issues with the gas valve to a pilot light that won’t stay lit or even blockages in the gas line. Let’s examine these potential problems:

  • Gas valve problems: If the gas valve on your furnace is closed or not functioning properly, it could prevent the gas from reaching your furnace. This could lead to inadequate heating or the furnace failing to start at all.
  • Pilot light not staying lit: The pilot light on your furnace is crucial for igniting the gas and heating your home. If the pilot light refuses to stay lit, it could be due to a faulty thermocouple, a clogged pilot orifice, or issues with the gas supply.
  • Gas line blockages: Blockages in the gas line can prevent the gas from reaching your furnace, leading to inadequate heating or a complete system shutdown. Such blockages could be due to dirt, debris, or even pest infestations.

If you suspect issues with the gas supply, it’s imperative to seek professional help immediately. Working with gas lines can be dangerous and should always be handled by trained professionals. At Sub Zero Temp Control, our expert heating repair services can safely and effectively address any issues with your gas supply and ensure your furnace is operating optimally.

Key Takeaways

Having your furnace stop working, particularly during the colder months, can be a significant inconvenience. However, understanding the common reasons behind furnace failures can help you diagnose the problem and take the necessary steps towards fixing it. The most common issues include lack of power, thermostat malfunctions, ignition problems, poor air flow due to dirty air filters or blocked vents, malfunctioning blower motors, and issues with the gas supply.

While some minor issues can be rectified by homeowners, it’s always recommended to seek professional help when dealing with more complex problems or whenever you’re in doubt. Regular furnace maintenance is also key in preventing many of these issues and ensuring your heating system runs efficiently.

If you’re facing any furnace issues, remember that Sub Zero Temp Control is here to help with professional furnace repair in Vancouver. Our expert technicians can diagnose and fix any furnace problems, ensuring your home remains warm and comfortable.


In conclusion, a furnace can stop working due to a variety of reasons, ranging from simple issues like a lack of power or thermostat issues to more complex problems like a malfunctioning blower motor or issues with the gas supply. Regular maintenance and prompt professional intervention when problems arise can ensure that your furnace functions optimally, providing you with consistent warmth and comfort.

At Sub Zero Temp Control, we understand the inconvenience of a non-functional furnace, especially during the cold winter months. That’s why we offer fast, reliable, and professional heating repair services to address any furnace issue that you may encounter. Our team of skilled technicians is committed to restoring your home’s comfort as quickly and efficiently as possible.

So, the next time you find yourself asking – “What is the most common reason a furnace stops working?” Remember that the answer can vary. But irrespective of the reason, Sub Zero Temp Control is here to provide the solution. Don’t let furnace problems leave you out in the cold – reach out to us for expert help!

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