How to Light a Furnace Pilot

How to Light a Furnace Pilot

Lighting a furnace pilot is a straightforward task that most homeowners can handle with care and patience. Before you begin, confirm the furnace is off and the gas valve is in the 'pilot' position. Working at the furnace's control knob and burner area, you will follow a specific sequence to ignite the flame safely.

Step 1: Prepare the Furnace

• Turn the furnace power switch to off and set the thermostat to its lowest setting.
• Remove the furnace access panel to expose the burner assembly and pilot light area.
• Locate the gas valve knob, which typically has settings for Off, Pilot, and On.

Step 2: Purge the Gas Line

Turn the valve to Pilot and hold it in. This position allows gas to flow to the pilot tube. Wait a few seconds after turning the knob to clear any trapped air or residual gas from the line.

Step 3: Ignite the Pilot

While continuing to hold the valve knob in, use a long-reach lighter or match to ignite the pilot tube opening near the burner. Keep the knob depressed for 30 to 60 seconds after the flame catches, giving the thermocouple time to heat up and confirm the flame is stable.

Step 4: Release and Confirm

Slowly release the valve knob. The pilot flame should remain lit; if it goes out, repeat the process. Once the pilot holds steady, turn the knob to On and restore power to the furnace.

When to Call a Professional

If the pilot refuses to light, the flame is weak or yellow, or you smell gas, stop and contact a qualified HVAC technician. A persistent pilot outage can signal a faulty thermocouple, a clogged pilot tube, or a gas supply issue that requires professional diagnosis.