Troubleshooting Natural Gas Furnaces: Tips for Common Issues.

Troubleshooting common issues with natural gas furnaces involves checking the thermostat and air filters. Here’s what you can do to solve some common problems.

Natural gas furnaces are an essential part of keeping your home warm, especially during the colder months. However, when these furnaces experience issues, it can be frustrating and concerning. In this guide, we’ll look at some common problems that natural gas furnaces can suffer and some troubleshooting steps to fix them.

From problems with the thermostat to issues with the furnace’s air filters, we’ve got you covered. Keep reading to find out how to keep your natural gas furnace running smoothly and efficiently all winter long.

Troubleshooting Natural Gas Furnaces: Tips for Common Issues.


Understanding The Basics Of Natural Gas Furnaces

Natural gas furnaces are essential components of residential and commercial heating systems and use natural gas as a source of fuel. An efficient furnace ensures that your property stays warm during the winter months. Understanding the basics of natural gas furnaces is crucial for identifying and fixing common issues that can cause your furnace to malfunction.

Below are the key points you should know about natural gas furnaces.

The Working Principle Of A Natural Gas Furnace

A natural gas furnace uses fuel and combustion to produce heat. The heat generated heats up air, which is then circulated throughout your property via ductwork by a fan. The air gets heated when it flows over a heat exchanger.

The working principle of a natural gas furnace is based on four significant processes.

  • Combustion: This process produces heat by burning natural gas.
  • Heating: The heat generated by combustion heats up the air.
  • Distribution: A system of ductwork distributes the heated air to various rooms in your property.
  • Controlling: The thermostat controls the temperature of the heated air.

The Various Components Of A Natural Gas Furnace

The following are the essential components that make up a natural gas furnace.

  • Gas pressure: This controls the flow of gas to the furnace.
  • Igniters: These are used to light up the burners and start the combustion process.
  • Burners: These are responsible for burning natural gas to produce heat.
  • Heat exchanger: This is where the heat is transferred to the circulating air via a series of pipes.
  • Filters: These are located in the return air ducts and are used to filter out dust and other particulates from the air circulating in your property.

Gas Pressure, Igniters, Burners, Heat Exchanger, And Filters – Their Basic Functions

  • Gas pressure: It regulates the amount of fuel flowing to the burners.
  • Igniters: These are used to ignite the fuel in the burners, starting the combustion process.
  • Burners: These are the components where the combustion of natural gas occurs, producing heat.
  • Heat exchanger: This component transfers heat from the combustion process to the circulating air via a series of tubes.
  • Filters: They remove dust and other particulates from the air, ensuring better indoor air quality.
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Common Reasons For Furnace Malfunction

Finding out why your furnace isn’t working can be challenging. However, being aware of the most common reasons for furnace malfunction can make it easier to identify and solve any issues.

  • Dirty filters: Dirty filters can cause your furnace to malfunction, resulting in poor indoor air quality.
  • Broken thermostat: When the thermostat fails to regulate the temperature properly, your furnace may not work as expected.
  • Ignition problems: Ignition problems can prevent your furnace from starting or cause it to shut down.
  • Clogged burners: Clogged burners can prevent the natural gas from burning correctly, resulting in a malfunctioning furnace.
  • Faulty heat exchanger: A faulty heat exchanger can cause your furnace to stop functioning correctly, resulting in poor indoor air quality.

Understanding the basics of natural gas furnaces and the components involved plays a vital role in identifying and fixing common problems. Regular maintenance and professional cleaning services can keep your natural gas furnace running correctly.

Troubleshooting Common Natural Gas Furnace Issues

Keeping your natural gas furnace in good working order is essential to maintaining comfort throughout the colder seasons. However, if your furnace suddenly stops functioning optimally, it can be a frustrating experience. Here are some tips for addressing common natural gas furnace issues:

Check The Thermostat Settings

  • Thermostat settings may be preventing the furnace from starting. Ensure that the thermostat is set to heat, and the temperature is at the normal level.
  • The power source might have gotten disconnected or shut-off. Check that the wiring is connected correctly and that the power is on.

Look For Tripped Circuit Breakers Or Blown Fuses

  • Tripped circuit breakers or blown fuses are frequently to blame for furnace failures. Check your electrical panel for these issues and reset if necessary.

Check For A Dirty Or Clogged Filter

  • A dirty or clogged filter can reduce the efficiency of your furnace or cause it to shut down. Replacing air filters regularly and keeping them clean is good practice.

Inspect The Furnace Wiring For Damage

  • Wires damaged by rodents or regular wear and tear can prevent your furnace from working correctly. Before replacing any damaged wires, be sure to turn off the power supply.
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Assess The Furnace Filters For Blockages

  • Blocked filters can cause furnace components to overheat and eventually, shut down. This issue may be prevented by regularly replacing or cleaning the filters.

Look For Clogged Or Dirty Ducts

  • Clogged or dirty ducts prevent warm air from circulating throughout your home. Cleaning air ducts is an essential task that should be performed periodically.

Check For Insulation Gaps Around Windows, Doors, And Walls

  • Inadequate insulation causes significant heat loss. Reducing insulation gaps around windows, doors, and walls helps keep your furnace from overworking.

Inspect The Furnace Burners For Obstructions

  • Clogged burners restrict airflow, causing components to overheat and creating shut-downs. Regular inspection of burners can help to prevent this problem.

Check For Loose Or Damaged Parts, Such As Fan Belts Or Bearings

  • Loose or damaged parts can cause a range of issues with furnace operation. A licensed technician can diagnose and repair these problems efficiently and safely.

Inspect The Furnace For Debris Or Foreign Objects

  • Foreign objects or debris can obstruct airflow to the furnace, causing it to shut down. Regular cleaning of the furnace ensures that the furnace runs optimally.

Look For Leaks In The Ductwork

  • Duct leaking can reduce the efficiency of your furnace and negatively impact energy bills. Checking your ductwork frequently and sealing any leaks is advisable.

Remember, if you attempt any of these troubleshooting tips, always prioritize safety above all else. When in doubt, it’s always best to contact a licensed professional to perform the work for your gas furnace inspection.

Preventive Maintenance For Natural Gas Furnaces

Natural gas furnaces are an essential component of any indoor heating and ventilation system. However, these appliances might sometimes malfunction and expose you to various issues such as safety hazards and increased energy bills. That is why it’s crucial to conduct regular preventive maintenance to ensure the furnace operates optimally.

Here are some tips to help you keep your natural gas furnace running efficiently.

Regular Filter Replacements

The furnace air filters are an integral part of the furnace system. The air filters stop dust and foreign particles from entering the furnace and reduce the potential for damage. It’s advisable to replace the furnace filter once a month or every three months, depending on the filter type, frequency of use, and the manufacturer’s recommendations.

You can also examine the filters every month to check if they’re dirty and clean them if needed.

Annual Professional Inspection And Cleaning

It’s recommended to schedule an annual inspection and cleaning by a professional hvac technician to ensure your furnace is running efficiently and burn your natural gas safely. The technician will check the furnace’s burners and heat exchangers for corrosion and damage while inspecting the essential components such as the thermostat, gas connections, and electrical wiring for any issues that can compromise the furnace’s performance.

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Clearing Any Debris Surrounding The Furnace

Debris such as dust, leaves, and debris, can accumulate around the furnace and obstruct its ventilation system and efficiency. Ensure that there’s ample space around the furnace to allow for proper airflow, and remove any debris or clutter that may prevent proper operation.

Lack of ventilation can cause the system to overheat and shut down or cause carbon monoxide to build up in your home, causing severe health risks.

Proper Ventilation And Airflow

Natural gas furnaces require adequate ventilation to ensure safe and efficient operation. Ensure that the furnace is free from obstructions, and the ductwork system is in good working condition to provide proper ventilation. Blocked air vents in different parts of the house would make the system work harder than necessary, leading to increased energy bills and reduced system efficiency.

Investing In A Programmable Thermostat

A programmable thermostat allows you to manage your furnace settings efficiently and reduce your energy consumption. It’s advisable to invest in a programmable thermostat to improve your furnace’s efficiency, conserve energy and reduce your energy bills. You can set the thermostat to lower temperatures when the home is unoccupied, saving up to 10% on your energy bills.

By following these tips, you can keep your natural gas furnace running efficiently and cost-effectively. Conducting regular preventive maintenance and inspection and ensuring proper ventilation, filtration, and airflow will help you keep your furnace in excellent working condition while ensuring the safety of your loved ones.


After reading this article, you should have a better understanding of some common issues with natural gas furnaces and how to troubleshoot them. Remember to always perform regular maintenance on your furnace to prevent any potential issues from arising. If you do experience an issue, start by checking the simple solutions before calling a professional.

Keep in mind that safety should always be your top priority when dealing with gas appliances. If you are ever unsure about what to do, or if you smell gas, evacuate your home and call for professional help immediately. By following these tips and being proactive about maintenance, you can ensure that your natural gas furnace continues to run efficiently and effectively for years to come.


I am a mechanical engineer and love doing research on different home and outdoor heating options. When I am not working, I love spending time with my family and friends. I also enjoy blogging about my findings and helping others to find the best heating options for their needs.