Why your gas water heater’s pilot light won’t stay lit and how to fix it fast

A gas water heater’s pilot light that won’t stay lit can be more than just a minor inconvenience—it can leave you without hot water when you need it most. Luckily, this is a problem that you should be able to resolve fairly quickly, especially if you stick with us.

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Note: The information provided in this article may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

Read more: How & why to vent your gas water heater: Options, safety tips & steps for proper installation

Common reasons why a water heater pilot light won’t stay lit & DIY solutions

1. Faulty thermocouple

This part senses when the pilot light is lit. If the thermocouple is dirty, misaligned, or damaged, it won’t signal the gas valve to stay open, which can cause the water heater pilot light to go out repeatedly. 

How to fix it:

• Look over the thermocouple for any debris or damage. Clean it if needed.
• Make sure the thermocouple is properly aligned with the pilot flame.
• Replace the thermocouple if it’s damaged. 

2. Clogged pilot orifice

A blocked-up pilot orifice can prevent gas from flowing to the pilot light, which can cause the flame to be too small to stay lit. 

How to fix it:

1. Shut off the gas supply to the water heater.
2. Carefully clean the debris in the pilot orifice with compressed air or a fine wire.
3. Try relighting the pilot light to see if it works after cleaning.

3. Faulty gas control valve

A malfunctioning gas control valve can prevent gas from properly flowing to the pilot light, which can cause the flame to extinguish.

How to fix it: Check for gas flow when trying to ignite the pilot light. If there’s no gas or the pilot goes out after lighting, then you may need to replace the valve.

4. Air in the gas line

Air trapped in the gas line can prevent the water heater pilot light from staying lit, especially if the gas supply has been turned off or interrupted recently.

How to fix it: Turn off the gas and allow the air to bleed out by attempting to light the pilot several times.

5. Drafty environment

If your water heater is installed in a drafty location, strong air currents can blow out the pilot light. This is especially common in poorly sealed garages or outdoor installations, where exposure to wind is higher.

How to fix it:

1. Close or seal any open or drafty windows, doors, or vents near the water heater.
2. Install a draft shield or relocate the water heater.

Read more: Common water heater problems and DIY fixes

How to reset a Honeywell water heater with a pilot light that won’t stay lit

If you happen to be dealing with a Honeywell water heater pilot light that won’t stay lit, here are the steps to reset it:

1. Set the gas control valve to the “OFF” position and wait for five minutes.
2. Turn the control knob to the “PILOT” setting.
3. Press down the control knob and light the pilot light with a long lighter. Hold the knob down for 30-60 seconds to let the thermocouple heat up.
4. After the pilot light stays lit, turn the gas control knob to the “ON” position to reignite the burner.

Gas water heater FAQs

Find answers to some of the most common questions about gas water heaters.

How do I know if my thermocouple is bad?

A bad thermocouple can cause the pilot light to go out or not stay lit. Your unit may have a faulty thermocouple if the pilot light won’t stay lit after you light it, or the flame is weak or irregular. If the thermocouple is dirty, bent, or damaged, it should be cleaned or replaced as needed.

Can I replace the thermocouple on my water heater myself?

Yes! Make sure to turn off the gas supply before attempting any repairs. 

Why does my pilot light go out when I release the pilot button?

If the pilot light goes out when you release the pilot button, the thermocouple may not be detecting the flame correctly. This could be due to a dirty or misaligned thermocouple or a gas valve issue. Cleaning or replacing the thermocouple should resolve the problem.

Read more: How to clean a water heater thermocouple to keep your unit running smoothly

More DIY help at your fingertips

Thanks for stopping by! We hope this guide helped you fix your water heater.

If you run into any issues, just give us a call at 1-877-477-7278 or start a chat with a pro on our website so we can help you through it. We’ve got many more troubleshooting and repair guides on our DIY blog and YouTube channel, plus all the parts you need to do it yourself at AppliancePartsPros.com. 

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