How to Restart a Furnace?

As an HVAC enthusiast, I know how crucial a well-functioning furnace is in maintaining a comfortable home environment.

Occasionally, a furnace may need a simple restart to return to its optimal working condition. This guide aims to help homeowners understand the basic steps involved in restarting different types of furnaces.

Whether it’s a gas furnace, oil furnace, heat pump, or modern furnace, each type requires a unique approach, and safety should always be your top priority.

Please remember, if the problem persists, it’s best to seek professional assistance. Let’s explore the procedures you should follow to safely restart your furnace.

Overview of Restarting a Furnace

Types of Furnaces

Different types of furnaces have unique characteristics, and therefore, the restart procedure can differ slightly. We’ll be focusing on gas furnaces, oil furnaces, heat pumps, and modern furnaces.

Gas Furnace

Step 1: Locate the Gas Furnace

The first step in resetting a gas furnace is finding the furnace. It is typically located in the basement, attic, or a dedicated utility closet.

Step 2: Turn Off the Gas Furnace

For safety purposes, make sure to turn off the furnace before you start the reset process. This is usually accomplished by flipping the power switch, often found near the furnace or on a nearby wall.

Step 3: Shut Down the Gas Supply

Look for the gas valve and turn it off. This is a necessary step to ensure safety while working on the furnace.

Step 4: Wait for a Few Minutes

After you have shut down the gas supply, wait for a few minutes. This waiting period allows any residual gas to clear out of the system before you restart the furnace.

Step 5: Turn the Gas Supply On

Once you have waited for a few minutes, turn the gas supply back on.

Step 6: Ignite the Pilot Light

You can find the instructions for igniting the pilot light in the furnace’s manual. Some modern gas furnaces are equipped with an electronic ignition system, so reigniting the pilot light manually is not necessary.

Step 7: Turn the Furnace On

After the pilot light is lit again, you can turn the furnace back on by flipping the power switch.

Remember, if your gas furnace fails to operate normally after the reset, it’s recommended to call a professional HVAC technician. They have the knowledge and expertise to accurately diagnose and solve furnace issues.

Oil Furnace

Step 1: Find the Oil Furnace

Your oil furnace is usually located in a basement, utility closet, or similar area in your home. Start the reset process by locating the furnace.

Step 2: Switch Off the Furnace

Ensure the furnace is turned off before beginning the reset process. This safety measure can typically be accomplished by turning off the power switch.

Step 3: Locate the Reset Button

The reset button on an oil furnace is typically a red button located on the burner motor or stack control switch.

Step 4: Press the Reset Button

Press the reset button to reset the furnace. Remember, you should only press the reset button once. Multiple attempts can flood your furnace with heating oil.

Step 5: Wait for the Furnace to Start

After pressing the reset button, wait a few moments for the furnace to start. If it doesn’t start or if it shuts off quickly after starting, there could be a deeper issue that needs professional attention.

Step 6: Call a Professional if Necessary

If your oil furnace isn’t responding to the reset or is displaying other issues, it’s time to call in a professional. They will have the knowledge and tools to accurately diagnose and solve the problem.

Remember, safety is paramount when dealing with heating equipment. If you’re unsure about any part of the process or the furnace continues to show signs of malfunction, it’s best to seek professional help.

Heat Pump

Step 1: Locate the Heat Pump

Begin by locating the heat pump, which is typically placed outside the house.

Step 2: Turn Off the Heat Pump

Before starting the reset process, ensure to switch off the heat pump. You can do this by turning off the circuit breaker that controls the heat pump.

Step 3: Wait for a Few Minutes

After turning off the heat pump, wait for a few minutes to ensure that the system is fully powered down.

Step 4: Press the Reset Button

After waiting, locate the reset button on the outdoor unit. It’s usually marked and easy to find. Press the reset button to restart the heat pump.

Step 5: Turn the Circuit Breaker Back On

Once you’ve pressed the reset button, go back to your circuit breaker and switch it back on.

Step 6: Check if the Heat Pump is Working

After turning the circuit breaker back on, go outside to check if the heat pump is operating correctly.

If your heat pump doesn’t start after this process or it’s not functioning as expected, it’s advisable to call an HVAC professional.

They have the skills and knowledge to correctly diagnose and fix any issues with your heat pump. Remember, it’s better to ensure your safety and the longevity of your system than attempting to fix an issue that’s beyond basic troubleshooting.

Modern Furnace

Modern furnaces often have an ignition source instead of a pilot light. If your furnace isn’t starting, try turning off the power at the breaker panel and then turn it back on after a minute or two.

Safety Precautions

Shut Off All Power Sources

Before you attempt to restart any furnace, shut off all power sources. This includes the circuit breaker, power switch, and light switch associated with the furnace. This step is crucial to ensure your safety during the process.

Disable Ignition Source

If your furnace has an ignition source like a pilot light or pilot flame jet, ensure it is shut off before attempting to restart the furnace. This can usually be done by turning the gas control valve to the off position.

Preparing to Restart the Furnace

Before restarting your furnace, take a few moments to inspect it for any visible issues. Check for a dirty air filter, which could be causing your furnace to overheat and shut down. Ensure there is sufficient fuel in the oil tank (for oil furnaces). If everything looks good, you’re ready to proceed with restarting the furnace.


Restarting a furnace can seem like an intimidating task, but with a clear understanding of your furnace type and a focus on safety, it’s a task you can typically handle yourself.

Remember, though, if the furnace continues to malfunction after a restart attempt, it’s time to call in the professionals. Unresolved issues can lead to more significant problems down the line, including expensive repairs. Keep your home comfortable and your furnace in top shape with routine maintenance and timely interventions.

This guide should serve as a helpful starting point in understanding your furnace and how to handle a simple restart. But remember, there’s no substitute for a professional’s expertise when it comes to the more complex aspects of furnace care and repair. Stay warm, and stay safe!

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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