When the temperature outside drops, there’s nothing more comforting than the warmth of a gas furnace. However, if your furnace suddenly stops working, it can leave you stranded in the cold. Before you call a professional, check if your gas furnace needs a simple reset. A furnace restart is a simple process that you can do yourself. In this article, we’ll guide you through the steps to ensure your gas furnace restarts and heats your home again.

1. Introduction: Understanding Your Gas Furnace and Its Components

Understanding the basic components of your gas furnace is essential to maintaining its efficient operation. A gas furnace typically consists of three primary components: the burner, which ignites and heats the air; the heat exchanger, which transfers the heat to the air; and the blower, which moves the heated air throughout the house.

To operate your furnace, you need to use the thermostat to set the temperature, which triggers the furnace to turn on the burners and heat the air. As the air is heated, it passes through the heat exchanger, which then distributes the warm air through the ductwork in your home. Finally, the blower circulates the heated air, letting you enjoy a comfortable and warm indoor environment.

1.1. Burner

The burner is the component responsible for directly igniting the gas and heating the air. This component should be kept clean and free of debris, such as dirt and dust, to prevent any obstructions that may interfere with its proper function. Over time, the burner may accumulate dirt and corrosion, which can cause it to malfunction. If the burner isn’t working properly, the furnace may not be able to heat your home efficiently.

1.2. Heat Exchanger

The heat exchanger plays a critical role in transferring heat from the burner to the air. The heat exchanger is designed to draw in cool air and heat it up as it passes through the unit. Over time, the heat exchanger can become damaged or develop cracks due to extended use or lack of maintenance. This can lead to a buildup of potentially deadly carbon monoxide gas, so it is important to keep your heat exchanger in good condition and have it inspected regularly by a professional.

By understanding the basic components of your gas furnace, you can take the necessary steps to maintain good operation. Regular maintenance and inspection by a professional are key to ensuring your furnace runs smoothly, efficiently and most importantly, safely.

2. Step-by-Step Guide to Restarting Your Gas Furnace

Restarting a gas furnace may seem daunting, but the process is fairly simple if you follow these step-by-step instructions.

Step 1: Turn Off the Power

Before you begin any work on your furnace, make sure to turn off the power source. This usually means turning off the circuit breaker or removing the fuse for the furnace.

Step 2: Check the Thermostat

Ensure that your thermostat is set to “off” or at a lower temperature than your desired room temperature. This will make sure that the furnace doesn’t turn on while you are restarting it.

Step 3: Inspect the Furnace

Take a close look at the furnace for any signs of damage or leaks. If you see any issues, do not attempt to repair them yourself – call a professional.

Step 4: Turn on the Gas

Locate the gas valve to your furnace and turn it on. Most valves have a lever that should be perpendicular to the gas line when it is open.

Step 5: Restart the Furnace

Press and hold down the furnace’s reset button for a few seconds. If your furnace doesn’t have a reset button, turn the power back on and wait for the furnace to ignite.

Step 6: Wait for the Furnace to Heat Up

Be patient and wait for the furnace to heat up to your desired temperature. This may take a few minutes, especially if your furnace has been off for an extended period.

Following these steps should get your furnace up and running in no time. Remember to always prioritize safety and call a professional if you encounter any issues.

3. Common Issues with Gas Furnaces and How to Troubleshoot Them

Gas furnaces are reliable heating appliances that provide warmth during cold weather. However, like any other machine, gas furnaces experience a variety of issues that can cause them to malfunction. Some of the common problems with gas furnaces include:

1. No Heat
If your gas furnace fails to provide heat, the first thing to check is the thermostat. Ensure that the thermostat is set to heat mode and the temperature is set correctly. If the thermostat is working but the furnace still doesn’t provide heat, check the air filter. A dirty air filter can cause the furnace to overheat and shut down the system. Replace the air filter if it’s dirty and restart the furnace.

2. Strange Noises
Gas furnaces can produce various noises due to different issues. A grinding noise could indicate a problem with the furnace’s blower wheel, while a rattling noise might mean that something is loose inside the furnace. If you hear strange noises coming from your furnace, turn off the system and call a qualified HVAC technician to diagnose the issue.

3. Constant Cycling
If your gas furnace keeps switching on and off frequently, it could be due to a few reasons. One common cause of this issue is an overheating furnace caused by a dirty air filter or a malfunctioning thermostat. Check the air filter and replace it if needed. Additionally, make sure that all air vents are unobstructed and open.

By troubleshooting these common problems, you can save time and money in gas furnace repairs. However, if you’re unsure or uncomfortable with troubleshooting the issue, don’t hesitate to call a professional HVAC technician to help you out.

4. Safety Precautions to Take Before Restarting Your Gas Furnace

Gas furnaces can be hazardous if not handled properly. Before restarting your gas furnace, ensure that you take necessary safety precautions to prevent any accidents or further damage to your system. Below are a few safety tips to consider:

Turn Off Electrical Power and Gas Supply

Before attempting to restart your gas furnace, make sure to turn off the electrical power and gas supply to the system. This can be done by finding the main power switch or breaker and turning it off. Likewise, the gas supply valve should also be turned off to prevent any gas leaks or explosions.

Check for Gas Leaks

Gas leaks can be hazardous and can cause fires or explosions. Before restarting your gas furnace, check for any gas leaks. The easiest way to check for leaks is by using a gas leak detector. If no detector is available, you can use a solution of soap and water to check for leaks. Apply the solution to all gas connections and look for any bubbling. If you find any leaks, do not attempt to restart the furnace and call a professional immediately.

Clean and Inspect the Furnace

Before restarting your gas furnace, clean and inspect the system thoroughly. This includes checking the furnace filters, blower motor, and burners. Replace any dirty or clogged filters and clean the blower motor and burners as necessary. Dirt and debris can cause your furnace to malfunction or operate inefficiently.

By following proper safety precautions, you can prevent accidents and ensure that your gas furnace runs smoothly and efficiently. However, if you encounter any issues or are unsure about any steps, always call a professional for assistance.

5. Tips for Maintaining Your Gas Furnace for Optimal Performance

When it comes to keeping your gas furnace running smoothly and efficiently, regular maintenance is key. Here are a few tips to help you maintain your furnace and avoid costly repairs:

Schedule Annual Inspections

One of the most important things you can do to maintain your gas furnace is to schedule an annual inspection with a professional HVAC technician. During the inspection, the technician will check your furnace for any signs of wear and tear, clean the components, and make any necessary repairs.

Replace Air Filters Regularly

Another important maintenance task is to replace your furnace’s air filters regularly. Dirty air filters can restrict airflow to your furnace, causing it to work harder and use more energy. In addition, they can allow dust and debris to build up in your furnace, reducing its efficiency and potentially causing damage.

Keep Your Furnace Area Clean

It’s also important to keep the area around your furnace clean and free of dust and debris. This can help prevent clogs and keep your furnace running smoothly. In addition, make sure that there are no flammable materials near your furnace, such as paper, cardboard, or chemicals.

Check Your Thermostat Settings

Finally, make sure that your thermostat settings are correct for your heating needs. If your furnace is running constantly, it may be because your thermostat is set too high. Adjusting your thermostat settings can help save energy and keep your furnace running smoothly.

By following these tips, you can help maintain your gas furnace and keep it running efficiently for years to come. If you have any questions or concerns about your furnace, don’t hesitate to contact a professional HVAC technician.

6. When to Call a Professional for Gas Furnace Repairs or Maintenance

While it can be tempting to try and fix a gas furnace issue yourself, sometimes it’s best to leave it to the professionals. Here are some instances where you should consider calling a professional for gas furnace repairs or maintenance:

1. No Heat

If your gas furnace has stopped producing heat, it could indicate a potential issue with the pilot light, thermostat, or ignition system. These components are all complex and should only be handled by a licensed professional. Attempting to fix these issues yourself could lead to further damage and pose a danger to your safety.

2. Strange Noises

If your gas furnace is making strange noises such as banging, rattling or popping, it’s often a sign that something is wrong. This could be due to a variety of issues, including a problem with the blower or motor. A professional can diagnose the issue and fix the problem before it gets worse and leads to further damage.

3. Carbon Monoxide Leaks

Carbon monoxide leaks are one of the most dangerous issues a gas furnace can have. Symptoms of carbon monoxide poisoning include headaches, dizziness, nausea, and fatigue. If you suspect a carbon monoxide leak, evacuate your home immediately and call a professional to come and repair the issue.

While gas furnace repairs can be costly, attempting to fix the issue yourself can often lead to even more expensive repairs down the line. Hiring a professional ensures that the job is done right the first time, saving you money and ensuring your safety.

7. Conclusion: Keeping Your Gas Furnace Running Smoothly and Efficiently

In conclusion, maintaining your gas furnace is critical in keeping it running smoothly and efficiently. Some simple steps can help keep your furnace in top shape:

Regular Maintenance

Regular maintenance keeps your furnace running smoothly, prevents breakdowns, and increases its lifespan. Change your furnace filter every three months or as recommended by the manufacturer. Inspect the furnace and its components regularly to ensure that they are in good condition. Call for professional maintenance when needed.

Energy Efficiency

An energy-efficient gas furnace saves money on your energy bills and reduces your carbon footprint. Consider upgrading to a high-efficiency furnace with an Annual Fuel Utilization Efficiency (AFUE) rating of 90% or more. Install a programmable thermostat and set it to lower temperatures when you are away from home or asleep.

Safety Measures

Gas furnaces can pose safety hazards, so it is essential to take precautions. Install carbon monoxide detectors on every level of your home and test them regularly. Keep flammable materials away from the furnace. Have a professional inspect the furnace and its components, including the gas lines, at least once a year.

By following these tips, you can keep your gas furnace running efficiently and safely for many years. Remember to always take safety precautions and call for professional repairs or maintenance when needed.

People Also Ask

What are the reasons why a gas furnace won’t restart?

A gas furnace may not restart due to a malfunctioning thermostat, clogged air filter, dirty flame sensor, or a faulty thermocouple. Other possible causes are a malfunctioning ignition system or a gas valve that needs repairing.

How can I safely restart my gas furnace?

To safely restart a gas furnace, turn off the furnace’s power supply and gas supply valve. Wait at least five minutes to allow any gas to dissipate. Then, switch the power and gas supply back on and follow the manufacturer’s instructions on how to relight the pilot light.

What should I check if my pilot light won’t stay lit?

If the pilot light won’t stay lit, check the thermocouple, which may need cleaning or replacement. Also, make sure the gas supply valve is fully open and that the pilot light flame is touching the thermocouple tip. If the problem persists, call a professional technician for assistance.

What should I do if I smell gas coming from my furnace?

If you smell gas coming from your furnace, turn off the furnace’s gas valve and power supply immediately. Open all doors and windows to allow fresh air to circulate and evacuate the building. Then, call your gas company or a qualified technician to inspect the gas lines and furnace for leaks.

When should I call a professional for furnace repairs?

It is advisable to call a professional technician for furnace repairs if the furnace emits strange noises, fails to start, or exhibits any other potential safety hazard, such as carbon monoxide leaks. Regular professional maintenance can also detect potential problems early and prevent costly repairs.


Restarting a gas furnace requires following specific safety procedures and precautions. Simple issues such as a tripped breaker or clogged air filter can cause a gas furnace to stop working, but more critical issues like a faulty ignition system or a malfunctioning valve can lead to dangerous gas leaks. It is important to recognize when to seek professional assistance to resolve furnace problems and to ensure that regular maintenance keeps the furnace operating safely and efficiently.