How to Adjust the Pilot Light on a Lennox Furnace

The proper functioning of your Lennox gas furnace can be undermined by an improperly adjusted pilot light. Set too high, and unnecessary fuel is wasted as the furnace is running, or set too low, and the flickering or sputtering pilot fails to ignite the heating element. Setting your furnace’s pilot light correctly is an easy adjustment and helps ensure the efficient operation of the heating system.

Things You'll Need

• Flashlight
• Screwdriver
• Matches

Instructions

1. Open the access door on the lower front of the furnace.

2. Position yourself where you can view the pilot light. If the pilot light flame is sputtering or less than approximately ½ inch in height, the flame needs adjustment.

3. Increase the height and gas feed of the flame by turning the small adjustment screw located on the front of the pilot light assembly counterclockwise. If the pilot flame is too low, it will sputter or fail to stay lit.

4. Decrease the height of the pilot flame if it exceeds ½ inch in height or there appears to be a small space at the base of the flame. If the gas feed is too high, excess fuel is wasted because more gas than is needed is flowing out of the pilot tube.

Tips & Warnings

• Keep some wood matches handy during the adjustment of the pilot light to relight it if it goes out.

Resources

• Lennox: Comfort Tips For Lennox HVAC Systems