Why Does Your Water Heater Pilot Light Keep Going Out?

When you step into the shower expecting a blast of warm water and instead get an icy wake-up call, it’s frustrating, to say the least. Often, the culprit of a water heater that won’t deliver hot water is a pilot light that keeps going out. This tiny but mighty flame is essential to your gas water heater’s operation, and when it fails, it can cut into you and your family’s comfort.

This blog will explore why your water heater pilot light keeps going out, common causes, and how to troubleshoot safely. Plus, we’ll review when it’s time to call a professional to address the issue.

What Does a Pilot Light Do?

The pilot light is a small, continuously burning flame designed to ignite the water heater’s main burner when heat is needed. Modern gas water heaters use pilot lights because they provide on-demand heat. Pilot lights help keep your water heater efficient and reliable by igniting the burner only when heating is necessary.

A pilot light’s primary function is to ignite the gas released by the burner when the thermostat signals that the water temperature has dropped below the set point. Without it, the burner cannot heat the water within your tank, leading to an unexpected (and likely unwelcome) supply of cold water.

How a Pilot Light Works

Here’s how it works in simple terms:

1. The pilot light burns constantly, fueled by a small amount of gas supplied through a dedicated gas line.
2. When the water heater needs to heat the water, the thermostat opens the main gas valve, allowing gas to flow to the burner.
3. The pilot light ignites this gas, creating a larger flame that heats the water in the tank.
4. Once the water reaches the desired temperature, the thermostat shuts off the gas to the burner, but the pilot light remains lit to be ready for the next heating cycle.

If your hot water heater’s pilot light keeps going out, it means something is disrupting this small but essential component. Understanding why can help you fix the issue quickly.

Common Reasons Why Your Pilot Light Keeps Going Out

A pilot light on a water heater can go out for several reasons, often related to issues with the gas supply, air flow, or the components maintaining the flame. Here are the most common causes:

Faulty Thermocouple 

The thermocouple is a safety device designed to shut off the gas supply if the pilot light goes out, preventing gas from leaking into your home. It works by detecting the heat from the pilot flame. However, if the thermocouple is damaged or worn out, it may mistakenly cut off the gas supply even when the pilot light is functioning correctly.

Signs of a Faulty Thermocouple:

• The pilot light won’t stay lit even after multiple attempts to relight it. 
• Visible damage, corrosion, or bending in the thermocouple.

Gas Supply Issues 

Your water heater depends on a steady supply of gas to keep the pilot light burning. When the gas supply is insufficient or interrupted, the pilot flame may go out. Possible gas supply issues include:

• Low Gas Pressure: Leaks or general maintenance issues with the gas line could reduce pressure. 
• Gas Line Problems: Clogs, blockages, or kinks in the gas line may restrict gas flow. 

Drafts or Airflow Disruptions 

Are there unexpected drafts or airflow near your water heater? Air currents from open windows, fans, or doors can extinguish the flame. Poorly sealed vents or chimneys may also cause backdrafts that blow out your pilot light.

Dirty Burner 

A dirty or clogged burner can cause the pilot flame to weaken or go out entirely. Dust, soot, and debris can accumulate over time and affect the burner’s ability to operate effectively. A clean burner is essential for a strong, stable flame.

Faulty Gas Control Valve

The gas control valve regulates the flow of gas to both the pilot and the burner. If it’s malfunctioning, it might not deliver a consistent supply, causing the pilot to go out.

Moisture or Corrosion

Water heaters in damp environments can develop rust or corrosion on components like the pilot assembly or burner, which can interfere with the flame’s stability.

Worn-Out Parts

Over time, components like the pilot tube or igniter can degrade, leading to inconsistent performance and outages.

How to Diagnose and Fix a Water Heater Pilot Light Issue

If your water heater pilot light won’t stay lit, follow these step-by-step troubleshooting tips to determine the cause and address it safely.

Step 1: Safety First 

• Turn off the gas supply before starting any troubleshooting. Look for the gas shutoff valve and ensure it’s completely closed. 
• If at any time you smell gas, evacuate your home immediately and call your gas provider or emergency services. 

Step 2: Ensure Proper Gas Supply 

• Test other gas appliances in your home to see if they’re functioning properly. If none of them work, the issue may be with your gas supply line.

Step 3: Clean the Burner 

• Turn off the gas and power to the water heater. 
• Use a small brush to remove dust, soot, or debris blocking the burner or pilot light assembly. 
• Wipe down components with a damp cloth and ensure everything is dry before relighting.

Step 4: Relight the Pilot Light 

Once you’ve completed your checks, it’s time to relight the pilot.

1. Turn the control valve to the “OFF” position and wait 5–10 minutes to ensure any residual gas clears. 
2. Set the valve to “PILOT” and press the reset button while using a long lighter to reignite the flame. 
3. Hold the reset button for 30–60 seconds to ensure the pilot flame remains stable. 
4. Once stable, turn the valve to the “ON” position.

If the pilot light still won’t stay lit after troubleshooting, it’s time to contact a professional.

When to Call a Professional

Recurring Issues 

If you’ve tried relighting your water heater pilot light multiple times and it still won’t stay lit, a certified Jacobs technician can help diagnose the root cause and make necessary repairs.

Older Water Heaters 

Water heaters over 8–10 years old may require more frequent maintenance or could be nearing the end of their lifespan. If problems with the pilot light persist, it might make more sense to replace the unit with a newer, more efficient model.

Gas Leaks or Safety Concerns 

Gas leaks are serious and should only be handled by professionals. If you notice a rotten egg smell or hear hissing near the gas line, leave your home immediately and contact emergency services or your gas provider.

Jacobs Keeps Your Water Heater Running Smoothly

When your water heater’s pilot light keeps going out, it’s more than just an inconvenience. It’s a sign that something needs attention. From a faulty thermocouple to drafts or gas supply issues, understanding the root cause can help you take the right steps to resolve the problem and keep your water heater running efficiently.

Remember to prioritize safety when working with gas appliances. If you experience persistent issues or feel unsure about handling repairs, call a Jacobs Heating & Air Conditioning expert who can handle the job safely and effectively. A little proactive maintenance care can go a long way in ensuring a reliable supply of hot water for your home.