How to Light a Furnace Pilot Light
The Pilot Light on a gas furnace can go out for several reasons. At this time of year however, the most common reason to light the furnace pilot light, is that its been off all summer long and simply was not needed when the air conditioner was running! As we prepare our homes for the cold season ahead, one thing that many of us have to do is learn how to light the furnace pilot light!
Since the late 1980′s and beyond, gas furnace manufacturers have been moving away from standing pilot light systems that are described in this article. Instead of wasting energy on the pilot light systems, most newer gas furnaces have moved to a solid state ignition system, where the gas furnace is lit “on demand” by either a spark system or a hot surface ignitor system, that glows and fires off the furnace.
In this article at the Gas Furnace Guide, we are going to take a look at the parts of a gas furnace pilot light, and how to light the pilot when it goes out!
Gas Furnace Pilot Light
As seen in the image to the right, there are only a few parts that make up the gas furnace pilot light system.
- Gas Supply Piping and Shut Off Valve
- Gas Valve Supply Control Knob
- Gas Pilot Light Primer Button
- Pilot Light Tubing
- Thermocouple or Pilot light Flame Sensor
The way the pilot light systems is pretty basic. When the gas is turned on at the supply shutoff petcock, the gas valve has a supply needed to fuel the gas furnace. There is a safety system inside the gas valve that will not allow it to open and supply gas to the unit, until a message is sent to the valve, more or less signifying that the pilot light is lit and ready to burn the gas fuel.
How to Light the Pilot Light
First – Starting from a scratch point, you want to make sure the gas furnace is turned off, and that the thermostat is not calling for heat! This is a safety precaution and while the gas furnace should not start in full burn, you can never practice enough safety when it comes to gas appliances!
Next – Open the access panel on your gas furnace and locate the gas valve. You can generally find the gas valve very easily by looking at the point where the black iron gas pipe enters the side of your gas furnace.
Next – After you find the gas valve, turn on the gas supply valve (1) to make sure gas is being supplied to your furnace and gas valve, and rotate or set your Gas Supply Knob (2) to the “Pilot” setting on the knob.
Light the Pilot Light – Press and hold the gas pilot primer button (3) for several seconds and either press the ignition piezo, or hold the flame of a candle lighter or a long stem fireplace match at the tip of the pilot light orifice (4). Once the pilot lights, keep holding the pilot light primer button for an additional 15-45 seconds. This will allow the thermocouple (5) time to heat up, which opens the pilot valve and continues to allow the pilot light to stay lit!
Gas Appliance Safety
- If you are unsure about lighting your own furnace pilot light, most natural gas utility companies provide a free service to light it for you! It may take a few days, but you can rest assured it is done right and safely!
- Any time you have a gas appliance in your home, you should make sure to install at least one Carbon Monoxide Detector per floor! It’s a small price to pay for your family safety!
- Clear all clutter at least 3 feet away from your gas furnace, and keep the are clean at all times!
- Always make sure your home has a working fire extinguisher!
- If you ever smell natural gas, touch NOTHING, leave the house immediately and call 911 or the gas company from a neighbors home!
What to Do if the Pilot Won’t Light
There may be an occasion that your pilot light just won’t light and stay lit! If you have held the primer for a minute or longer and the pilot goes out every time, you may have a bad thermocouple or a bad gas valve. In most cases, it’s the thermocouple system, which is an affordable repair.
In any case, before you spend any time or money trying to diagnose and fix the problem yourself, it’s well worth calling out a local HVAC Contractor (Check reviews on Angies List) to diagnose the problem for you. You could spend several hundred dollars in parts alone and never get the furnace repaired! A service tech can find the right problem in just a few minutes!