1. Home

Video:How to Fix a Gas Furnace: Furnace Pilot is Out

with Erick Noack

Some gas furnaces require their pilot lights to stay on in order to work properly; if the pilot light goes out, it can be a potentially dangerous situation. Here's a video explaining how to fix a gas furnace when the pilot light goes out.See Transcript

  • All Videos
  • All Home Videos
  • Home Repair Videos

Transcript:How to Fix a Gas Furnace: Furnace Pilot is Out

Hi, my name is Erick Noack. I'm an HVAC technician for ABC Plumbing, Heating, Cooling, and Electric in the Chicagoland area for About.com. Today, we're going to show you how to light a standing pilot for a gas fired furnace.

Reasons a Pilot Light Might Go Out in a Gas Furnace

Some of the common sources of a lost pilot light are a failed thermocouple, a strong draft, or a clogged orifice to the gas supply to the pilot light. A thermocouple is a device on a standing pilot system that proves the flame to the gas valve and allows gas to keep flowing as long as there's a flame sensed. It's probably best if you have a professional check it out, clean it and verify that it's working properly. Now, the thing to keep in mind is most modern furnaces don't use a standing pilot light anymore.

Modern Gas Furnaces Won't Use a Pilot Light

To demonstrate lighting a pilot today, we're going to use a water heater that has a standing pilot. Most modern furnaces don't use pilot lights anymore. Some use pilot lights that only ignite when the call for heat starts. Some use a pilot light that burns continuously. The important thing to remember when you're lighting your pilot light is to read your manufacturers instructions, very important. We're dealing with gas here. Some pilots cannot be lit manually, they have to be lit by the furnace itself. Some pilots have to be lit manually, so that's why reading this label that comes on all appliances is critical when it comes to lighting a pilot light.

Re-Lighting a Pilot Light in a Gas Furnace

In this case, the first thing that needs to happen is that the thermostat needs to be turned all the way down to where it says pilot lighting. Next thing is to turn the valve to face pilot. That sets it up to where the pilot can be lit. The next thing you need to do is identify where the pilot is, and that's by following the tubes down inside into the burner. You're going to need a BBQ lighter or a long wooden match to reach inside where the pilot is. Once you have that pilot identified and light your lighter, then you want to go into there and be ready right at the pilot before you push this button down. When you push this button down, it sends gas to the pilot valve, and it will ignite once you introduce the flame. At that point, you need to hold that button down for about a minute and then release it. If the flame holds, it means the system is working. If the flame doesn't hold, you can try again and hold it longer, or you may need to have service.

Knowing a little bit about your system and being educated about it is the best way to stay on top of it and avoid breakdowns. Thanks for watching. To learn more, visit us on the web at About.com.

About videos are made available on an "as is" basis, subject to the User Agreement.

Promotional Feature: View this video series to learn how to take good care of your house.

©2014 About.com. All rights reserved.