Free Guide to Relighting Your Pilot Light

Understanding Your Pilot Light and Why It Goes Out

A pilot light is a small, continuous flame that stays lit inside your furnace, water heater, or gas fireplace. Its job is to ignite the main burner when your heating system needs to produce warmth. Think of it as a starter mechanism—when your thermostat calls for heat, the pilot light ignites the larger gas burner that actually heats your home or water.

The pilot light typically burns a small amount of natural gas or propane continuously, even when your heating system isn't actively running. You can usually see it through a small window on your furnace or water heater. The flame should be blue, with perhaps a small yellow tip. If the flame is mostly yellow or orange, or if it keeps going out, something may need attention.

Several common reasons cause pilot lights to extinguish. A draft or wind blowing across the pilot opening can blow out the flame. Dust or debris can block the small opening where gas flows to the pilot, preventing ignition. A worn thermocouple—a safety device that detects whether the pilot is lit—may no longer work properly and could trigger a safety shutoff. Sometimes the gas supply valve gets turned off accidentally. In older systems, the ignition electrode might be corroded or misaligned.

Weather changes can also affect pilot lights. During very cold periods, condensation may form in gas lines, or the burner assembly may contract slightly, affecting how the pilot sits. Similarly, some pilot lights simply reach the end of their service life after years of continuous operation.

Practical Takeaway: Before attempting to relight your pilot, identify which appliance has the problem—furnace, water heater, or fireplace—as each has slightly different procedures. Check whether you can see the pilot light area clearly and whether your equipment has an access panel. Knowing what you're working with makes the process safer and more straightforward.

Safety Precautions You Must Take Before Starting

Safety comes first when working with gas appliances. Gas leaks, while uncommon, present real dangers including carbon monoxide exposure and fire risk. Taking proper precautions protects you and your family.

Before you do anything, locate your gas shutoff valve. This is usually a lever or knob on the gas line leading to your appliance. It should be accessible and labeled. Turn this valve perpendicular to the pipe to shut off gas flow completely. Wait at least five minutes before attempting any work. This allows any residual gas to dissipate from the burner chamber.

Next, check for gas odor in the area. Natural gas companies add a chemical smell (mercaptan) so you can detect leaks. If you smell gas strongly, do not attempt to relight the pilot. Instead, leave the area, go outside, and call your gas company's emergency line. Do not use electrical switches, phones, or create sparks—go to a neighbor's house to make the call if needed.

Ensure adequate ventilation in the room where your appliance sits. Open nearby windows or doors slightly. Never work on a pilot light in a completely sealed, unventilated space. Have a flashlight ready before you start—do not use a match or lighter as your light source, as this creates unnecessary flame near your work area.

Wear clothing that won't catch fire easily. Avoid loose sleeves or dangling items that could contact a flame. Keep long hair tied back. Have a working fire extinguisher nearby, rated for gas and electrical fires (Type BC or ABC rated).

If you have any doubt about your ability to complete this task safely, or if your appliance is new and still under warranty, contact a licensed gas technician. They carry insurance and have specialized training for these systems. The cost of professional service is worth avoiding potential safety issues.

Practical Takeaway: Write down your gas company's emergency number and keep it near your phone. Know where your gas shutoff valve is located before you need it. These two steps alone prevent most dangerous scenarios from developing.

Step-by-Step Relighting Process for Furnaces

Furnace pilot lights require a specific sequence to relight safely. Most furnaces have a control valve with three positions: OFF, PILOT, and ON. Understanding this valve is key to the process.

Start by locating your furnace's control valve. This is usually a metal knob or lever on the gas line entering your furnace. Turn it fully to the OFF position and wait five minutes. Then, locate the ignition button—this is typically a red or black button near the control valve, labeled "IGNITE" or "PILOT." Some furnaces use a piezo igniter (a button you press repeatedly to create sparks) while others have electronic igniters that work automatically.

Once you've waited the full five minutes, turn the control valve to the PILOT position. Hold the valve in this position—most valves require you to press and hold them down while igniting. While holding the valve down, press the ignition button repeatedly (if using a piezo igniter) or once (if electronic). You should hear small clicking sounds and see sparks near the pilot opening. After pressing the ignition button 4-5 times, look through the sight glass to see if the pilot flame appears.

If the pilot lights, continue holding the valve down for another 30-60 seconds. This allows the thermocouple to heat up and signal the valve that ignition has occurred. Then slowly release the valve button. If the pilot light stays on after you release it, the thermocouple is working correctly. Wait a few more minutes, then turn the control valve to the ON position. Your furnace should now respond normally to your thermostat.

If the pilot doesn't light after 5-10 ignition attempts, stop and wait. Do not keep pressing the ignition button repeatedly—this floods the chamber with gas. Wait 30 minutes to let excess gas disperse, then try again. If it still won't light after a second attempt, the issue likely requires professional diagnosis.

Practical Takeaway: The key to furnace pilot relighting is patience and the 30-60 second hold after ignition. Rushing this step or releasing too early causes the pilot to go back out. Mark the time on your phone so you hold for the full duration without guessing.

Step-by-Step Relighting Process for Water Heaters

Water heater pilot lights operate similarly to furnaces but with some important differences. Most water heaters have the control valve and ignition button located at the bottom front of the tank, behind a removable panel or cover.

First, remove any access cover or panel blocking the burner area. This is usually held with one or two screws or clips. Set this panel aside safely. You should now see the burner assembly and the control valve. The control valve typically has markings for OFF, PILOT, and ON/HOT positions.

Turn the control valve fully to OFF and wait five minutes. Do not skip this step—water heaters can accumulate more gas than furnaces. After waiting, locate the pilot light opening. You may need to use a flashlight to peer into the burner chamber. The pilot opening is usually a small tube about the diameter of a pencil.

Turn the control valve to PILOT. Look for an ignition button on the valve itself—water heater ignition buttons are usually built into the valve assembly rather than separate buttons. Press and hold this button while simultaneously holding a long lighter or long match to the pilot opening. The pilot should ignite within a few seconds of flame contact.

Once lit, continue holding the button down for 60-90 seconds. Water heater thermocouples typically require longer heating time than furnaces. After this period, slowly release the button while watching the pilot through the opening. The flame should remain steady. If it does, replace the access panel and turn the control valve to ON or HOT (depending on your model's labeling).

Test your water heater after 15-20 minutes by running hot water at a sink. You should feel it warming. The main burner should have ignited when you turned the valve to ON. If you hear the burner but no warm water appears after several minutes, the water heater may have an internal issue requiring service.

Practical Takeaway: Water heater pilot relighting often requires a longer ignition hold time than furnaces—aim for 90 seconds rather than 30 seconds. Having