A Step-by-Step Guide: How To Light A Furnace

How To Light A Furnace


As temperatures drop, ensuring your furnace operates efficiently becomes paramount to maintaining a warm and cozy home atmosphere. However, encountering issues with furnace ignition can be frustrating. Yet, mastering the art of lighting a furnace can alleviate this frustration with simple steps and a keen eye for safety.

It’s crucial to acknowledge that not all furnaces utilize a pilot light, as many modern models incorporate electronic ignition systems. Nevertheless, for those with a pilot light, following specific steps is essential.

A Step-by-Step Guide: How To Pilot Light A Furnace:

Step 1: Prioritize Safety:

Safety should always come first. Take these precautions:

– Turn off the gas supply at the main valve.
– If you detect a gas odor or suspect a leak, vacate the premises immediately and contact your gas provider.

Step 2: Locate The Pilot Light Assembly:

The pilot light assembly is typically situated near the furnace’s bottom, often behind a small access panel. Components include the gas valve, pilot light, and thermocouple.

Step 3: Turn The Gas Valve To “Pilot:

Rotate the gas valve to the “pilot” position, enabling gas flow to the pilot light.

Step 4: Ignite The Pilot Light:

Press and hold the designated ignition button while using a long lighter or match to ignite the pilot light. Maintain the button press for approximately a minute to allow the thermocouple to heat up.

Step 5: Release The Button:

After a minute, release the ignition button. If the pilot light remains lit, proceed; if it extinguishes, wait and repeat steps 4 and 5.

Step 6: Turn The Gas Valve To “On:

Once the pilot light stays lit, switch the gas valve from “pilot” to “on,” allowing gas flow to the main burners for ignition.

Step 7: Replace the Access Panel:

Reinstall the access panel securely, covering the pilot light assembly.

By adhering to these steps, you can effectively light a furnace equipped with a pilot light. However, always prioritize safety and consult a professional if uncertainties arise.

Safety Tips For Lighting A Furnace:

– Check for Gas Leaks:

Utilize a gas leak detector or soapy water to detect gas leaks before ignition.

– Keep the Area Clear:

Remove flammable materials from the furnace vicinity to minimize fire risks.

– Use a Long Match or Lighter:

Employ long-reach tools to maintain a safe distance from the flame during ignition.

– Follow Manufacturer’s Instructions:

Adhere to specific instructions provided for your furnace model.

– Regular Maintenance:

Schedule routine maintenance to ensure optimal furnace functionality.

These safety tips mitigate risks and ensure a smooth furnace lighting process, promoting a safe and comfortable home environment.

Troubleshooting: Common Issues and Solutions to Light a Furnace:

Issue: The Pilot Light Won’t Stay Lit:

Solution:  Replace a faulty thermocouple, a relatively simple task for homeowners.

Issue: Dirty or Clogged Burners:

Solution:  Regular cleaning and maintenance prevent burner issues caused by dirt accumulation.

Issue: Gas Valve Problems:

Solution:  Contact a professional HVAC technician to diagnose and repair gas valve issues promptly.

Promptly addressing these common issues ensures uninterrupted furnace functionality throughout colder months.

Frequently Asked Questions About Lighting A Furnace:

How Do I know If My Furnace Needs To Be Lit?

Modern furnaces with electronic ignition systems don’t require manual lighting; older models with pilot lights need relighting if extinguished.

What Should I Do If The Pilot Light Doesn’t Stay Lit?

Clean the thermocouple and relight the pilot; replace the thermocouple if issues persist.

 Can I Light My Furnace If I Smell Gas?

No, evacuate immediately and contact a professional to address gas leaks promptly.

 Should I Have My Furnace Inspected By A Professional?

Yes, annual professional inspections ensure safe and efficient furnace operation, providing peace of mind to homeowners.


By addressing these common queries, homeowners can better manage furnace-related concerns, ensuring optimal functionality and safety during colder seasons.

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About the author


I am Ben , a seasoned HVAC specialist with over 6 of experience in the HVAC industry. I holds HVAC Certification and has a proven track record in providing expert advice on HVAC systems.