How to adjust the pilot light on gas logs

Updated April 17, 2017

Many newer homes have gas log fireplaces. Gas log fireplaces are used for both convenience and because they are ecologically friendly. Most gas log fireplaces have a pilot light system. This system permanently maintains a small flame that ignites the gas when the log fireplace is turned on. Occasionally the pilot light flame burns too low or completely goes out but it can be adjusted by most any homeowner using tools readily available in the home.

Turn the gas off and allow the area around the gas log to vent for at least five minutes prior to doing any work. After five minutes, there should be no odour of gas. If the odour of gas continues after turning the gas switch to the off position open several windows in the house and call the gas company.

Use a flashlight to illuminate the area and find the pilot light. It is usually located at the base of the logs. Follow the gas line coming in and the pilot light will be at the end of the line. The control knob will be located at the front right or left of the base of the log unit. It is normally covered by a metal grate.

Place to control knob in the pilot position and observe the pilot light. It should be a pale blue colour and slightly yellow at the top. The flame should encompass the thermocouple. The thermocouple is a small metal bulb located at the end of a copper tube.

Find the pilot light adjustment screw. It is usually located at the base of the pilot light where the gas line enters. Use a long handled, narrow tip, flathead screwdriver to turn the adjustment screw both in the clockwise and counterclockwise position. Turn the screw in the direction that will minimise the pilot flame. Then turn the screw back in the direction that expands the pilot flame so it fully encompasses the thermocouple.

Turn the control knob to the on position. Turn on the fireplace. Observe that the main log flame lights within a minute. Turn the control knob back to the off position and observe that the pilot light remains on. If the pilot light fails to remain on the thermocouple has air bubbles, is loose or has failed. Re-attempt to light the pilot light several times to make sure any air in the thermocouple has been removed.

Wait for the thermocouple to cool if the pilot light fails to remain on after removing the air bubbles. Turn the thermocouple clockwise to make sure it fits finger tight. A thermocouple fitted to loose or too tight may not work properly. If the thermocouple is finger tight and the pilot light will not stay lit, replace the thermocouple.


Thermocouples are small sensors that are designed to turn off the gas if the pilot light goes out. While the thermocouple is hot the gas line will stay open, and if the thermocouple cools the gas line closes. This is a safety feature to prevent gas from filling a room if the pilot light extinguishes.

Things You'll Need

  • Flashlight
  • Flathead screwdriver
  • Gas log in thermocouple
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author