Relight Furnace Pilot Light: The Safe, Simple Guide

Understanding how to relight furnace pilot light is a fundamental skill for any homeowner, especially during the colder months. A faulty thermocouple, a common issue related to gas furnaces, often leads to the pilot light extinguishing itself, requiring manual relighting. Safety guidelines provided by organizations like the National Fire Protection Association (NFPA) are crucial when dealing with gas appliances. Utilizing the right tools, such as a long-handled lighter or match, ensures a safe and effective process. Consider the guidance of a certified HVAC technician for complex issues but learning how to relight furnace pilot light empowers you to address simple situations promptly.

Image taken from the YouTube channel AMRE Supply , from the video titled Furnace - How to Relight a Pilot Light | Repair and Replace .

Relighting Your Furnace Pilot Light: A Safe & Simple Guide

This guide provides step-by-step instructions on how to relight your furnace pilot light safely and effectively. Before you begin, remember that working with gas appliances requires caution. If you are uncomfortable with any of these steps, or if you smell a strong gas odor, immediately contact your local gas company or a qualified HVAC technician.

Safety First: Preparation & Precautions

Before even thinking about striking a match, take these important precautions.

Identifying a Gas Leak: The Smell Test

• Smell for Gas: The most obvious sign of a problem is the distinct smell of gas. Natural gas companies add a sulfur-like odor (mercaptan) to make leaks easily detectable.
• What to Do If You Smell Gas: If you smell gas:
  • Do not operate any electrical switches (lights, appliances, etc.).
  • Do not use your phone within the building.
  • Immediately evacuate the building and contact your gas company or emergency services from a safe distance.

Gathering Your Tools & Materials

• Long Lighter or Match: A long butane lighter or a fireplace match is crucial for safely reaching the pilot light without burning yourself.
• Screwdriver (Possibly): You might need a screwdriver (usually flathead or Phillips) to access the pilot light assembly, depending on your furnace model.
• Flashlight: Good visibility is essential. A flashlight will help you see the pilot light assembly clearly.
• Safety Glasses (Recommended): Protect your eyes from any potential debris.

Understanding Your Furnace: Model & Location

• Locate Your Furnace: Typically, furnaces are found in basements, utility rooms, or closets.
• Identify Your Furnace Model: Knowing the make and model of your furnace can be helpful if you need to consult the manufacturer's instructions or find diagrams online. A label with this information is usually located on the furnace itself.

Step-by-Step Guide to Relighting the Pilot Light

This section provides a general guide. Always refer to your furnace manufacturer's instructions if available, as specific steps may vary.

1. Turn Off the Gas Supply

• Locate the Gas Control Valve: This valve is usually located on the gas supply line near the furnace.
• Set the Valve to "OFF": The valve typically has three positions: "ON," "OFF," and "PILOT." Turn the valve to the "OFF" position. This will cut off the gas supply to the pilot light and main burner.
• Wait: Allow at least five minutes for any residual gas to dissipate before proceeding. This is crucial for safety.

2. Access the Pilot Light Assembly

• Locate the Access Panel: Most furnaces have an access panel that covers the pilot light assembly.
• Remove the Access Panel: You may need a screwdriver to remove screws or latches holding the panel in place.

3. Set the Gas Control Valve to "PILOT"

• Locate the "PILOT" Setting: Once the access panel is removed, locate the gas control valve again.
• Turn to "PILOT" and Press: Turn the valve to the "PILOT" position. Some furnaces require you to press and hold a button while in this position to allow gas to flow to the pilot light.

4. Light the Pilot Light

• Position the Lighter/Match: Hold the lit lighter or match near the pilot light opening.
• Press and Hold: While holding the lighter/match near the opening, continue to press and hold the pilot button on the gas control valve. You should hear a hissing sound as gas flows to the pilot. The pilot light should ignite.
• Maintain Pressure: Continue to hold the pilot button for about 30-60 seconds after the pilot light ignites. This allows the thermocouple to heat up and keep the pilot light lit.

5. Verify the Pilot Light Remains Lit

• Release the Pilot Button: After 30-60 seconds, slowly release the pilot button.
• Observe the Pilot Flame: The pilot light should remain lit. If it goes out, repeat steps 3 and 4. If it repeatedly goes out, there may be a problem with the thermocouple or gas supply, and you should contact a qualified HVAC technician.

6. Set the Gas Control Valve to "ON"

• Turn to "ON": Once the pilot light remains lit, turn the gas control valve from the "PILOT" position to the "ON" position.

7. Replace the Access Panel

• Secure the Panel: Carefully replace the access panel and secure it with screws or latches.

8. Test the Furnace

• Adjust Thermostat: Turn up your thermostat to call for heat. The main burner should ignite.
• Monitor Operation: Observe the furnace for proper operation. Listen for unusual noises and ensure the heat is being distributed as expected.

Troubleshooting Common Issues

If the pilot light fails to light or stay lit, consider these common issues:

Dirty Pilot Light Orifice

• Description: A build-up of dust or debris can block the gas flow to the pilot light.
• Solution: Carefully clean the pilot light orifice with a small wire or compressed air. Refer to your furnace manual for specific cleaning instructions. Do not use anything that could damage the orifice.

Faulty Thermocouple

• Description: The thermocouple is a safety device that senses the pilot flame. If it's faulty, it won't allow the gas valve to stay open.
• Solution: A faulty thermocouple usually needs to be replaced. This is best left to a qualified HVAC technician.

Weak Pilot Flame

• Description: A weak flame might not properly heat the thermocouple.
• Possible Causes: Low gas pressure, a dirty pilot light orifice, or a malfunctioning gas valve.
• Solution: Check for gas supply issues and clean the pilot light orifice. If the problem persists, contact a qualified technician.

Drafts

• Description: Strong drafts can blow out the pilot light.
• Solution: Eliminate any drafts near the furnace.

When to Call a Professional

While relighting a pilot light can often be a DIY task, there are times when it's best to call a qualified HVAC technician:

• Repeated Pilot Light Outages: If the pilot light repeatedly goes out, there's likely an underlying problem that needs professional attention.
• Unfamiliar with the Process: If you're not comfortable with any of the steps outlined in this guide.
• Strong Gas Odor: If you smell a strong gas odor, evacuate the building and call your gas company or emergency services immediately.
• Damaged Components: If you notice any damaged components on the furnace.

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