How to Light the Standing Pilot on a Gas Furnace

The standing pilot (sometimes referred to as a pilot light) is one in which the flame is lit at all times. Its purpose is to serve as a small ignition flame for the gas burner. When the thermostat signals for gas to be delivered from the gas valve to the burner, it is the standing pilot that ignites the gas to heat the air in the combustion chamber. And when this little flame fails to operate properly or goes out, it’s one of the most common reasons a gas furnace fails to operate.

The pilot light on a gas furnace can go out because of drafts. To relight the pilot, follow the manufacturer’s instructions exactly; they are usually fastened to the furnace. If instructions for relighting the pilot are not provided, follow this general procedure:

Preparing to Relight the Pilot

A pilot going out is a very common problem with older furnaces, and is even more frustrating when you don’t know how to relight it. It is quite easy, though. The steps involved can vary slightly depending on your furnace model and pilot valve type, so if possible, find the instructions adhered inside the furnace door cover or in the furnace’s instruction manual.

Two of the most common types of pilot valve body assemblies will have either a red reset button and a gas valve, or no reset button and a valve knob that can be depressed. But whichever type you have, if you have an older model furnace with a standing pilot (flame is lit all the time) then this is the basic procedure:

  1. Turn your thermostat to a setting that will demand heat (like 85 degrees). Make sure the thermostat is set to the HEAT mode.
  2. Go to the furnace and find the pilot valve. The pilot valve body is a box-shaped device into which the main gas line will run; it is located near the gas burners. It will usually have a gas cock or valve knob that reads ON, PILOT, and OFF. Locate this gas cock or knob.
  3. Turn the knob or gas cock to the OFF position and wait about three minutes for any residual gas to clear away.
  4. Find the pilot tube and nozzle. It’s located near the gas burner tube assembly inside the furnace.
  5. Get your match or lighter ready. Sometimes the pilot is hard to reach. If possible, try and use a long fireplace match when you light it.


Relighting the Pilot

  1. Turn the gas valve off for at least three minutes to let any escaped gas dissipate.
  2. Press and hold the valve while you turn it to “Pilot.”
  3. Use a long BBQ lighter to relight the pilot light. Keep the valve pressed in for at least five seconds to make sure the pilot light remains lit.
  4. If the pilot light stays lit, turn the valve to “On.” If it doesn’t stay lit, repeat these steps.
  5. Replace the panel cover.


What Caused My Pilot Light to Go Out?

Pilot lights go out for a variety of reasons. Some of the top reasons include:

  • A problem with the gas supply
  • A cracked heat exchanger
  • A thermocouple malfunction

It is important to note that any disruption to the gas or propane supply will cause the pilot light to go out. Often, these issues arise during construction in other parts of a home. Other issues occur as a furnace grows older, like a cracked heat exchanger or a broken thermocouple.


Important Notes

Here are some important things to remember about re-lighting your furnace pilot light.

  • If you have followed the above steps on how to light a furnace more than twice and the pilot light won’t light or won’t stay lit when you release the “Reset” button, something is wrong with the furnace and you need to contact a furnace professional.
  • Don’t try to light a furnace without first turning it off. Excess gas can cause serious damage in the home and can also lead to injury.
  • Other than the pilot light, do not attempt to fix your furnace yourself unless you are knowledgeable in furnace repair. While the furnace itself may be safe, gas can be dangerous.
  • If you do not have a long match or long lighter, using a tightly rolled piece of paper to put distance between you and the igniting pilot light will work.

Final Thoughts

As cold weather approaches, it is important to take a few preventative measures to protect your home through the chilly months. Whether your pilot light will not stay lit or you think your furnace may not be running optimally, you can always count on the Aire-Tech to keep your home warm. Perhaps you need repairs, new furnace installation, or preventative maintenance—whatever the HVAC issue is, Aire-Tech is ready to help.

If your system needs repair or inspection before winter, call us on 951-926-1002. You can also visit our Contact page and complete the contact form.