When winter temperatures drop, one of the most common furnace problems homeowners face is a furnace pilot light out situation. If your gas furnace suddenly stops producing heat, a blown-out pilot light is often the cause.
The good news? In many cases, you can safely relight it yourself—if you follow proper gas safety steps. This guide explains how to relight a pilot light furnace correctly, what to watch out for, and when it’s time to call a professional HVAC technician.
How to Relight a Pilot Light Furnace
Follow these steps carefully. If your furnace has manufacturer instructions inside the access panel, follow those first.
Step 1: Turn Off the Gas
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Locate the gas control valve on the furnace
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Turn the knob to OFF
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Wait at least 5 minutes to allow any gas to clear
This step is critical for safety.
Step 2: Locate the Pilot Assembly
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Remove the furnace access panel
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Find the pilot burner and thermocouple
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The pilot is usually a small metal tube near the main burners
Step 3: Set the Gas Valve to “PILOT”
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Turn the gas control knob to PILOT
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Press and hold the knob (this allows gas to flow to the pilot)
Step 4: Light the Pilot Flame (Manual Ignition)
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While holding the knob down, use a long lighter
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Light the pilot burner
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You should see a steady blue flame
Step 5: Hold the Reset Button (Important)
How long to hold the pilot button down?
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Hold it for 30–60 seconds
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This allows the thermocouple to heat up
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If released too soon, the flame will go out again
Step 6: Turn the Gas Back On
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Slowly release the knob
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Turn it on
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Replace the access panel
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Turn the thermostat back to HEAT
Your furnace should start heating within a few minutes.
How to Know If the Pilot Light Is Successfully Lit
A properly lit pilot flame should be:
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Blue (not yellow or orange)
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Steady, not flickering
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Touching the thermocouple tip
If the flame goes out immediately after releasing the button, there’s likely a component issue.
What to Do If the Pilot Light Won’t Stay Lit
If your gas furnace pilot light relight attempt fails repeatedly, common problems include:
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Dirty or failing thermocouple
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Blocked pilot tube
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Weak gas pressure
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Draft issues
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Aging furnace controls
At this point, repeated relighting is not recommended.
When to Call a Professional HVAC Technician
Call a licensed HVAC technician if:
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The pilot light won’t stay lit
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You smell gas at any point
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The thermocouple needs replacement
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Your furnace is over 15 years old
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Heat is inconsistent or unreliable
This is also the right time to consider furnace maintenance or heating repair services.
Maintenance Tips to Prevent Pilot Light Issues
Prevent future problems with these HVAC best practices:
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Schedule annual furnace tune-ups
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Keep the furnace area clean and draft-free
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Replace worn thermocouples early
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Inspect burners and pilot assemblies yearly
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Address heating issues before peak winter
Regular maintenance improves safety, efficiency, and furnace lifespan.
Final Thoughts: Know When to Stop DIY and Call an Expert
Relighting a pilot light can be a simple fix, but persistent pilot problems are a warning sign. Gas furnaces are not the place for guesswork. If your furnace pilot light keeps going out or you’re unsure about any step, the safest move is to contact a licensed HVAC professional.
Need help right now? Contact a trusted local HVAC technician for furnace repair, emergency heating services, or annual furnace maintenance to keep your home safe and warm all winter.
