How to Relight Your Furnace Safely: 7 Steps to Get It Right the First Time

March 20, 2023
Furnace maintenance in Roseville, MI

The pilot light is a critical component of a gas furnace. It ensures safety, efficiency, and comfort in your home. If you ever notice that your pilot light has gone out, it’s essential to relight it as soon as possible to ensure that your furnace is functioning correctly.

What Is a Pilot Light?

The pilot light is a small gas flame that burns continuously in a furnace. Its job is to ignite the main burner when the thermostat calls for heat. When the thermostat detects that the room temperature has fallen below the set temperature, it sends a signal to the furnace to turn on. The pilot light then ignites the gas in the burners, which heats up the air that is circulated throughout the home.

If you’ve noticed that your pilot light has gone out and you’re not sure how to relight it, don’t worry. The following seven steps will guide you through the process of relighting your furnace:

1. Turn Off the Power

The first step to safely relight your furnace is to turn off the power to the furnace. You can do this by turning off the switch on the electrical panel that controls your furnace.

Turning off the power to your furnace is important for two reasons: (1.) It helps you avoid damage to your equipment and (2.) It helps you avoid injury. Electrical shock can cause serious injury or death.

2. Turn Off the Gas

Next, you’ll want to turn off the gas supply to the furnace. You can do this by turning the valve on the gas line that leads to your furnace.

Make sure you don’t smell any gas before proceeding. You can accidentally leak gas into your home while you try to relight it, and that can be dangerous.

3. Wait for the Gas to Dissipate

After turning off the gas, you should wait for the gas to dissipate before attempting to relight the furnace. This usually takes around 5-10 minutes, depending on the size of your furnace. If necessary, open a window to make sure all gas smells are gone before you attempt to relight it.

4. Locate the Pilot Light

Once the gas has dissipated, you can locate the pilot light. This is the small flame located near the bottom of the furnace.

5. Relight the Pilot Light

To relight the pilot light, turn the pilot button to the “Pilot” setting. Press the pilot button and hold it down. While holding down the pilot button, use a long match or a lighter to ignite the gas at the pilot light assembly.

6. Hold the Reset Button

Once the pilot is lit, hold the reset button down for a few seconds to make sure the pilot stays lit, and then release the button. Typically, you should hold the furnace reset button for 30 seconds. If you don’t give it enough time, it may go out again, and you’ll have to start all over.

7. Turn on the Furnace

Turn the power to your furnace back on at the electrical panel. It should fire up right away and begin warming the home. If you’re still having issues, check your thermostat to make sure it’s set properly. If it is, contact a professional HVAC technician for assistance.


How can you tell if your furnace needs to be relit?

There are a few signs that can indicate that your furnace pilot light has gone out and needs to be relit. Here are some common signs to look out for:

  • No heat
  • Cold air
  • Smell of gas
  • Yellow burner flame

If you notice that your furnace isn’t heating up your home like it normally does, or if the air coming out of your vents is just not feeling as warm and cozy as you remember, there’s a good chance that you need to relight your furnace.

Does relighting your furnace take a long time?

Relighting your furnace is a quick, easy process that can be done in under an hour. The job may require a few simple tools that you already have on hand. The whole process takes less than an hour from start to finish.

How long will it take to warm your house up after a relight?

It depends on how warm your house is. If it’s already warm and you just need to get it back up to temperature, it should take about 20-30 minutes to warm your house up. If you’re starting from a cold house, it can take anywhere from 45 minutes to an hour or more to warm up fully.

If you have another heat source, such as electric space heaters, you can use them until the house gets warm enough.

Is it safe to relight your furnace’s pilot light yourself?

Yes, it’s totally safe to relight your furnace’s pilot light yourself. It might seem scary at first, but once you know how it works, and you’ve done it a few times, it becomes second nature. And if you really don’t feel confident doing it, you can call a technician for help.

What should you do if the pilot light won’t stay lit?

If the pilot light won’t stay lit, it’s usually because you’ve got a problem with the gas valve. If it is staying lit but not staying on long enough to ignite your burner, you might have problems with your thermocouple or flame sensor (or both).

The thermocouple is what allows your furnace to adjust its temperature based on how much fuel is being burned. If you have a gas furnace, it’s located inside the heat exchanger (the metal box). If you have an electric furnace, the thermocouple is located in the gas valve.

Sometimes, the thermocouple can get dirty or damaged, which will keep it from working properly. Your best bet is to call a professional if you’re having trouble with this issue—they’ll know exactly where to look and how to fix it quickly and efficiently!

If you follow the seven steps above, you should be able to safely relight your furnace. However, if you’re unsure about any of these steps or if you encounter any problems, it’s always best to call a professional HVAC technician to help you.

At C & C Heating & Air Conditioning, we’ve been providing quality service to clients throughout Macomb Township, MI for years. Our technicians are trained to handle any problem with your HVAC system from broken ducts to malfunctioning thermostats. And we’re happy to help you find the best option for your home’s needs, whether it’s installing a new furnace or upgrading your air conditioner. You can also turn to us for UV lighting, indoor air quality assessments, smart thermostats, and duct cleaning and repair and replacement. If you’d like more information on our services or how we can help improve your indoor air quality, contact us today!

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