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Pilot lights firing

How to Light a Pilot Light

Travis N.Verified

Maitenance Tech, Casto

Residential HVAC

486 positive ratings
Pilot Light Types

There are two types of pilot: those made before 1990 (standing) and those made after (automatic). Standing pilots need to be lit by hand. Automatic pilots tend to be electric.

A pilot light can go out for many reasons, and is a common occurrence. Often there are no other underlying problems except for an air draft that blew it out. Learn how to light your pilot whether it is a Standing Pilot Light and an Electronic Ignition system.  

Electronic ignition vs. standing pilot light

The type of furnace you have will determine how the main burners are lit. Newer model furnaces are equipped with an electronic ignition making them easier and more convenient to light. However, there are still many older model furnaces in use and that have the standing pilot light which will need to be manually re-lit.

A lit match

To determine what type of pilot light you have, first locate the label on your furnace for specific lighting instructions. These are convenient to have on hand; however, they can be hard to read if the print is small or the label is old and worn. Read on if you can’t find the instructions on your furnace.   

Standing pilot light

The pilot light is located behind the furnace control door. Some pilot lights have a reset button that is usually red, and a gas valve.

First, turn the thermostat to a temperature higher than room temperature to trigger the furnace to kick on. Also, make sure it is on the HEAT setting.

Next, locate the pilot light assembly. It should look like a box near the burner with the gas line coming into it. There should be a gas knob with ON, OFF and PILOT on it. It is important to turn it OFF first and wait three minutes to allow any extra gas to dissipate.

Have a long match or long lighter ready that you can use to light the pilot light. Now, turn the gas knob from OFF to PILOT. Hold the lit match or lighter near the pilot and hold the knob down for 30 seconds. Once the thermocouple warms up, the gas valve will open allowing the flame to stay lit. Now, slowly let go of the knob and turn it to ON. This will allow enough gas to light the main burner flame.

If this process does not light the pilot light, the thermocouple may be defective and need to be cleaned or replaced. Ask an HVAC technician for guidance on how to do this.

A pilot light turns on

Electronic pilot light

An electronic system produces ignition either with an intermittent pilot or a hot surface ignition. The intermittent pilot system uses an electronic controlled spark to ignite the gas and main burners, whereas the hot surface ignition uses an electronic heating element to control the gas burner. After ignition occurs the thermostat is able to call for heat like normal.

Since the electronic pilot light assembly can relight itself, check the electrical and gas connections first for problems. Then, if everything is fine, turn the power off to the furnace and shut off the gas supply. Wait several minutes to ensure the air is free of any leftover gas.

Now, turn the power and gas supply back on. Next, look for the pilot light assembly. There should be an ignition button and a small reset button close to each other. Press both buttons at the same time and once the pilot light is lit, do not let go of the smaller button for one minute. This allows the flame to heat up the flame sensor and keep it lit.

If the above does not light the pilot light, then the electronic ignition system may need to be replaced. This is a complicated procedure and could cause damage. Ask an HVAC technician for more help if necessary.

The pilot light can go out for any reason; however, the most common is due to a drafty room or open windows or doors. Built up dust can cause it to have no air flow and cut out as well. It should take you a short time and little money to re-light this pilot light yourself. However, if you have trouble lighting the pilot light or keeping it lit, there could be underlying problems. An expert can guide you through the process.


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