If a gas water heater loses its gas supply, relighting the pilot light becomes essential to resume heating. This small flame ignites incoming gas, enabling the system to heat water effectively. Without the pilot light, ignition won’t occur, and the heater remains inoperative. Fortunately, the process of restoring the pilot is typically straightforward. Here’s a simple guide to help you relight it safely and efficiently.
What Is a Pilot Light?
A flame that ignites gas inside the burner of your water heater is called pilot light. This small flame plays a critical role in heating water effectively. Unlike some assumptions, traditional models maintain this flame at all times, ensuring quick ignition when the system operates.
Types of Pilot Lights
- Traditional Models: These constantly burn, providing reliable operation but requiring occasional upkeep.
- Electronic Ignition Systems: These ignite gas only when needed, offering energy savings and advanced safety features.
How Does a Pilot Light Work?
A dedicated tube delivers gas to the pilot light, maintaining a small flame that remains active. This flame acts as the ignition source when the thermostat signals the need for heat. The burner ignites using this flame, heating the water in the tank. If the flame goes out, a safety mechanism halts the gas supply, minimizing potential risks. Modern systems equipped with electronic ignition incorporate sensors that detect flame presence, ensuring gas flow occurs only under safe conditions. These features work together to maintain both efficiency and safety in your water heater.
Signs Your Pilot Light Is Out
Recognizing the signs of an extinguished pilot light can help address issues quickly:
- Cold Water: A sudden lack of hot water usually points to an inactive burner, indicating the pilot flame has gone out.
- No Flame Visible: Inspect the small access window near the bottom of your water heater. If a flame isn’t visible, relighting is necessary to restore functionality.
- Unusual Noises: Clicking or hissing sounds could signal failed attempts to ignite the burner, often caused by a pilot light issue.
- Flickering Flame: If the flame appears weak or unsteady during operation, it might not stay lit for long, suggesting a problem requiring attention.
- Error Codes: Many modern water heaters display error codes or flashing indicator lights when the pilot light is out, making troubleshooting more straightforward.

Why Does the Pilot Light Go Out?
Various reasons can lead to the pilot light extinguishing unexpectedly. Identifying these causes can help you address and prevent recurring issues:
- Gas Pressure Changes: Variations in gas pressure interrupt the consistent flow, causing the flame to go out. Temporary drops often resolve quickly, but persistent issues may indicate a problem with external gas lines or the supply.
- Thermocouple Malfunctions: This component detects whether the pilot light is burning. A faulty thermocouple fails to sense the flame, shutting off the gas for safety. Regular inspections and replacements can mitigate this issue.
- Strong Air Currents: Wind entering through open doors, windows, or vents near the water heater can blow out the flame. Positioning the unit away from direct drafts helps prevent this problem.
- Restricted Airflow: Limited air supply disrupts combustion, preventing the pilot light from remaining lit. Clear any blockages from dust, debris, or tight installation spaces to maintain proper ventilation.
- Safety Mechanisms Activated: Residual gas left inside the unit triggers built-in safety features that prevent relighting until the excess dissipates. Allowing sufficient time before attempting to reignite the pilot ensures a safe process.
- Dirty Pilot Orifice: Accumulated dirt or soot in the pilot tube can block the gas flow, resulting in an extinguished flame. Cleaning this area periodically helps maintain consistent performance.
- Control Valve Failure: A defective control valve disrupts the flow of gas to the pilot, requiring professional replacement to restore functionality.
How to Relight the Pilot Light
Relighting the pilot light on your water heater can be straightforward if each step is followed carefully:
- Turn Off the Gas: Find the control knob on your water heater and rotate it to the “OFF” position. Allow at least 10 minutes for any remaining gas to dissipate before proceeding.
- Access the Pilot Assembly: Remove the access panel to expose the gas valve, pilot light nozzle, and, if present, the igniter button.
- Set to “Pilot”: Adjust the control knob to the “PILOT” position and press it down to initiate gas flow to the pilot light.
- Ignite the Flame:
- For Manual Systems: Use a long lighter or match to ignite the pilot while holding the control knob down.
- For Electronic Systems: Repeatedly press the igniter button until the flame becomes visible.
- Hold the Knob: Maintain pressure on the control knob for 30 to 60 seconds to ensure the flame remains stable.
- Turn the Gas On: Once the flame stabilizes, release the knob and turn it to the “ON” position. Close the access panel securely.
Troubleshooting Persistent Issues
If you unsure how to turn on pilot light on a water heater and relighting attempts are unsuccessful, investigate these potential causes:
- Blocked Tubes: Debris or kinks in gas lines may restrict flow. Inspect the lines and ensure they are clear and properly connected.
- Control Valve Malfunctions: A defective valve may fail to regulate gas flow correctly, requiring inspection and possible replacement.
- Ignition System Failures: Electronic ignition systems depend on sensors and circuits. Faulty components in these systems often need repair by a qualified technician.
- Improper Thermocouple Position: The thermocouple must align correctly with the pilot flame to function. Misalignment can cause the system to shut off the gas supply.
- Clogged Pilot Orifice: Dirt or residue in the orifice can block gas flow to the pilot light. Cleaning with a small wire or needle can often restore proper function.
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Can You Relight the Pilot Light Yourself?
If you’re unsure how to relight a hot water heater and the pilot light keeps going out, expert help is essential. A malfunctioning thermocouple or control valve could be the cause, often requiring replacement.
Ben’s Plumbing offers vast experience with water heater repairs in Seattle and neighboring areas. Our skilled technicians identify and fix issues quickly. If replacement is necessary, we guide you in choosing and installing a unit suited to your requirements. Known for outstanding service throughout Seattle, we also handle HVAC concerns to maintain year-round comfort. Wondering how to relight a pilot light on a water heater? Contact us today for reliable assistance!