How to Relight the Pilot Light on Your Furnace: A Step-by-Step Guide

When your furnace suddenly stops producing heat, an extinguished pilot light is often the culprit, especially in older gas furnaces. For Los Angeles homeowners, this usually shows up during cool evenings or early mornings when the heat is finally needed. If you’ve ever wondered how to relight a pilot light safely, this guide will walk you through the process step by step.

That said, safety always comes first. If you smell gas near your furnace or feel unsure at any point, it’s best to stop and call a professional.

First: What Is a Furnace Pilot Light?

A pilot light is a small, continuously burning flame that ignites the burners in older gas furnaces. While many modern systems use electronic ignition, plenty of LA homes still rely on furnaces with standing pilot lights.

When the pilot light goes out, the furnace can’t ignite, which means no heat, even if the thermostat is calling for it.

How Can You Tell If the Pilot Light Is Out?

Before relighting anything, it’s important to confirm the pilot light is actually the issue. Common signs include the furnace blowing cold air, the system failing to turn on at all, or the absence of the familiar burner ignition sound.

You can usually verify the pilot light by removing the access panel near the bottom of the furnace and looking for a small blue flame. If there’s no flame present, the pilot light is out.

If you smell gas near the furnace at any point, stop immediately and do not attempt to relight it.

How to Relight a Pilot Light Safely in 5 Steps

If you’ve confirmed the pilot light is out and there’s no gas odor present, you can carefully follow these steps. Always consult your furnace manual if available, as designs can vary slightly.

Step 1: Turn the Furnace Off

Set your thermostat to “off” and locate the gas control valve on the furnace. Turn the knob to the “off” position and wait at least five minutes. This allows any lingering gas to dissipate safely.

Step 2: Switch the Gas Valve to Pilot

After waiting, turn the gas control knob to the “pilot” position. You should see a button or knob that needs to be held down to release gas to the pilot.

Step 3: Light the Pilot Flame

While holding the pilot button down, use a long lighter or match to ignite the pilot. You should see a small, steady blue flame once it lights. Continue holding the pilot button down for about 30 seconds. This allows the thermocouple to heat up and signal that the pilot flame is present.

Step 4: Release and Observe

Slowly release the pilot button. If the flame stays lit, the pilot has been successfully relit. If it goes out immediately, the thermocouple or another component may be faulty.

Step 5: Turn the Furnace Back On

Turn the gas control knob to the “on” position, replace the access panel, and set your thermostat back to heat. The furnace should ignite normally.

What If the Pilot Light Keeps Going Out?

If your pilot light keeps going out after relighting, there’s likely an underlying issue that needs professional attention. Common causes include: 

• A dirty or failing thermocouple
• Drafts around the furnace
• A clogged pilot orifice
• An issue with your gas supply

Rather than repeatedly relighting the pilot light, give a professional a call. They can address the root cause of a faulty pilot light and identify and resolve issues that could lead to bigger problems and potential safety risks.

When You Should Not Relight the Pilot Yourself

There are times when DIY isn’t the right choice. If you smell gas near your furnace, hear hissing sounds, or notice soot buildup or corrosion around the burner assembly, do not attempt to relight the pilot.

In these cases, turning off the furnace and contacting a licensed HVAC professional is the safest option.

Get Help with Furnace Pilot Light Troubleshooting in Los Angeles

Relighting a pilot light can be simple, but recurring problems usually point to a deeper issue. At Brody Pennell Heating & Air Conditioning, we help Los Angeles homeowners diagnose pilot light problems, resolve safety concerns, and keep their heating systems running reliably.

If your furnace pilot light won’t stay lit, you smell gas near your furnace, or you’d simply rather have a professional handle it, contact Brody Pennell today to schedule furnace repairs.

Frequently Asked Questions About Furnace Pilot Lights

Can I relight a furnace pilot light myself?

Yes, many homeowners can safely relight a pilot light if there’s no gas odor and the furnace manual allows it. If the pilot won’t stay lit, professional service is recommended.

How can I tell if the pilot light is out on my furnace?

Common signs include no heat, the furnace not turning on, or seeing no blue flame through the access panel near the burner.

Should I turn off the furnace if the pilot light is out?

Yes. Turn the furnace off at the thermostat and gas valve before attempting to relight the pilot or calling for service.