How to Relight a Furnace Pilot Light in 8 Steps

April 26, 2023


If you own an old furnace, it probably has a pilot light—a blue flame that ignites the burner. Without that pilot light, there’s no flame to light the burner, meaning zero heat distribution. When the heat stops working, you’re left in the cold, wondering what to do. 

Utah and Nevada winters can get chilly, so your furnace pilot light must remain on to provide a warm home. Learning how to relight a furnace pilot light can help you avoid cold spells if the light goes out.

How Does a Furnace Pilot Light Work?

A gas line feeds a pilot light that ignites the gas supplying the furnace burner. A valve inside the furnace releases gas into the burner when the furnace is on. The pilot light ignites the gas that flows to the burner. If the pilot light goes out, the furnace won’t function.

How can you tell if your furnace contains a pilot light? Remove your furnace cover panel, which should reveal the small flame that is the pilot light. If you have a concern with your furnace pilot light and want professionals to handle it, just schedule a service right away. YES! will get you warmed up in no time!  Why Would a Pilot Light Go Out?

First of all, can you light a furnace by yourself? Yes, you can but first you need to identify the issue causing the flame to go out. 

Let’s discuss five culprits of an extinguished pilot light.

  1. Interruption to Your Gas Supply

Pilot lights rely on a consistent flow of gas to remain lit. However, if there’s a disruption to your gas supply, gas won’t flow, causing the pilot light to go out. Why would there be a disruption to your gas supply? The manual valve might be closed, or your utility company decided to shut off all gas going to your home because they’re doing maintenance. If you think the problem is the latter, contact your energy provider to confirm if there is ongoing maintenance service.

  1. Clogged Gas Tube

Remember, the gas tube supplies your furnace with gas and allows the flame to remain on. If the tube is clogged with dust and debris, there’s no gas flow, which would cause the light to go out. 

  1. Airflow Problems

Airflow can be a draft inside your home of which you’re unaware. A slight breeze can sometimes be enough to extinguish a furnace flame. You might also have leaking furnace ducts. When the output ducts leak air, the pilot light may go out. 

  1. Faulty Thermocouple

The thermocouple is a sensor that measures temperature and prevents unburned furnace gas from accumulating. If the sensor is damaged or misaligned, it won’t detect the flame, causing it to go out. If the thermocouple is loose, you can re-tighten it. If it’s a faulty device, a replacement is the best solution.

  1. Dirty Furnace

When dirt contaminates a furnace, its components won’t receive enough oxygen, causing the pilot light to extinguish. You can remove debris or contaminants from your pilot light mouth with a brush. However, the best cleaning method is professional assistance. 

An expert can help you identify the source of the issue and help you relight your furnace flame if needed. Call YES! at 844-216-9300 to schedule an HVAC service appointment in Nevada or Utah and get your furnace professionally serviced.  

Learn How to Relight a Furnace Pilot Light with These 8 Steps

First, never try to light a pilot light without turning off the furnace. Turning it off allows any lingering gas to dissipate. Here are eight steps to follow when attempting to light a furnace. 

  1. Assemble Your Tools

You’ll need a long match or a lighter. Length is critical because you don’t want to be too close to the flame when it ignites. If your furnace is in a dimly lit area, consider wearing a headlight or bringing a flashlight.

  1. Consult the Furnace Instruction Manual

Every furnace has an instruction manual with specific instructions on dealing with a furnace lighting problem. Use the manual for a step-by-step procedure relating to your furnace model.

  1. Locate and Remove the Access Panel

If your furnace has an access panel often located behind a sheet of metal that’s connected with screws, it should only take a minute to loosen them and remove the panel. Keep those screws in a safe place because they could easily get lost. You may find directions on how to light the furnace pilot light on the back of the access panel. 

If there are no instructions, follow the ones below for more directions.

  1. Locate the Control Knob and the “Reset”’ Button

The control knob is usually located somewhere near the bottom of the furnace. You’ll know that it’s the right knob when you see the words “On,” “Off,” and “Pilot.” These are three essential positions as we move on to the next steps. 

You can find the “Reset”’ button right next to the gas valve control knob, and it’s often distinguished by a red color.

  1. Turn off the Control Knob

Turn off the control knob so that gas stops flowing through the unit. Wait at least five minutes for any remaining gas to dissipate. 

You might want to set a timer to ensure when it’s safe to move forward. A timer will reduce the chances of any flare-ups when you light your match or spark your lighter. Remember, the furnace continues to run on gas even if the pilot light has been off for a while, so do not skip this step.

  1. Turn the Control Knob to the “Pilot” Position and Ignite a Lighter

Turn the control knob to the “Pilot” position. Ignite your lighter or light your match. Ensure that the lingering gas has evaporated, then press and hold down the “Reset” button as you bring the flame closer to the pilot light. 

The source of the flame can either be a lighter or a match. Safety tip: Keep your hands as far from the flame as possible. At this point, the light should catch on. 

If you’re unsure where the pilot light is, look at the tubes connected to the gas valve control box. The two smaller ones should lead you directly to the pilot light opening. Keep the “Reset” button pressed until you see a bright flame. 

Wait a few seconds, then release the “Reset” button.

  1. Turn the Gas Back On

Turn the gas valve control knob on to ignite the furnace burners. Ensure sufficient gas flow and that your furnace generates heat.

Remember to replace the furnace access panel after you’re done. 

  1. Seek Professional Assistance If the Flame Remains Off

If you followed all the steps above for relighting the pilot light and the flame still goes out, there might be underlying problems, such as a malfunctioning thermocouple. This would require expert-level assistance. If so, request a furnace inspection or furnace repair service by your local HVAC technicians. 

Contact YES! Professionals for Furnace Assistance

Learning how to relight a furnace pilot light can restore your heating unit and keep you warm during those frosty nights in Utah and Nevada. However, if you’re unsure how to do it or concerned about your safety, let the pros at YES! take over. 

Schedule a residential HVAC service by calling 844-216-9300, and we’ll send a qualified technician to restore your heating unit.

 

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Last Updated: September 26, 2024