Pilot lights on aging gas appliances sometimes won't stay on. When the pilot orifice gets clogged with soot and debris over time, gas cannot reach through the pilot orifice and maintain a flame. Fortunately, the problem is easy to prevent. Taking a little time to clean the pilot light can help keep the pilot on and prolong the appliance's life.
Turn off the gas to the appliance or furnace at the gas valve nearby, turning the valve so that it's at a right angle to the pipe. Wait five minutes for gas fumes to dissipate.
Remove the bracket that holds the copper thermocouple and pilot light assembly. Loosen and remove the two nuts that hold the thermocouple and pilot gas line, using an adjustable wrench or pliers.
Remove the pilot and thermocouple from the appliance. Place them on a table on top of an old towel.
Scrub the pilot with a stiff wire brush to remove the blackened residue near the tip. Use a metal file to clean stubborn soot and grime. Use an air compressor to blow away particles from the tip of the pilot light.
Replace the pilot light and thermocouple assembly, placing them back inside the appliance and affixing them to the bracket that holds them to the burner assembly. Reatttach the thermocouple and pilot gas lines to the appliance and tighten them with an adjustable wrench.