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A User's Manual for Relighting a Gas Furnace Pilot Light

by Sonja Albrecht
Repair Home Columnist

It happens from time to time, especially with older gas furnaces: the pilot light goes out. At this point you have two options: call a heating contractor, or pull out the user's manual and relight it yourself. What user's manual, you ask? If you don't have the original, simply follow these instructions for relighting a gas furnace pilot light.

There are two basic pilot valve types: one has a red reset button and a gas valve, the other just has a valve knob that can be pressed down. Both are standing pilots (the flame is always lit), standard in older model furnaces.

Here's how to relight a standing pilot light:

  1. Clear Residual Gas. Find the pilot valve body near the gas burners--it's a box-shaped device into which the main gas line runs. There should be a valve lever or knob with the settings 'On,' 'Off,' and 'Pilot.' Turn the knob to the 'Off' position and wait a few minutes for any residual gas to clear.
  2. Prepare the pilot. If you have a pilot with a red reset button, turn the gas valve from 'Off' to 'Pilot.' If you have a pilot with a knob you can press down, turn that knob from 'Off' to 'Pilot.'
  3. Relight the pilot. Place a lit match or lighter flame at the pilot while pressing and holding down either the red button or the knob. Keep pressing for about 30 seconds. This gives the thermocouple enough time to heat up and open the main gas valve.
  4. Turn the pilot 'On'. Slowly release the button or knob, and the pilot should stay lit. If not, repeat the relighting process and press the button or knob for slightly longer, 45-60 seconds. Then turn the valve setting to 'On.' The burners should ignite, and you're live.



If your pilot just won't light, contact an HVAC contractor. The cause may be a malfunctioning part, such as a loose thermocouple. Other possible causes are a clogged pilot orifice or an improperly adjusted flame setting.

Heating units can be temperamental. If relighting your gas furnace pilot proves difficult or impossible, don't get frustrated--get a heating contractor. There's no reason your quirky furnace should leave you out in the cold this winter.

About the Author
Sonja Albrecht works as a writer and editor for an online media company. She has also taught college writing and completed a Ph.D. in English.