To fix a water heater that won’t stay lit, first turn off the gas supply, clean the thermocouple with a sandpaper, and adjust its position. Then try lighting the pilot light again.
A malfunctioning water heater can quickly become a major inconvenience, and there’s nothing more frustrating than a pilot light that won’t stay lit. Fortunately, this common issue is often the result of a simple fix that can be done at home without the need for a professional.
In this article, we’ll cover the basic steps to take when your water heater pilot light is causing problems. We’ll explain how to troubleshoot the issue and get your unit working properly again. By following our tips, you can save time, money, and frustration.

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Checking The Pilot Light
A pilot light is a small flame that ignites the gas burner in your water heater. If the pilot light goes out, you won’t be able to get hot water. Checking the pilot light is the first thing to do when your water heater won’t stay lit.
Here are the steps to follow.
Step-By-Step Instructions For Checking The Pilot Light
- Locate the pilot light: Your water heater’s pilot light is typically located at the bottom of the tank. To access it, remove the burner cover.
- Check for a flame: Look through the sight glass to check if there’s still a flame. If there isn’t, it means your pilot light has gone out.
- Turn the gas valve to “off”: Before proceeding to relight the pilot light, make sure the gas valve is set to the off position. Switching off the valve is crucial for your safety.
- Wait for the gas smell to disperse: Give your heater at least 5 minutes for natural gas to disperse to ensure maximum safety before proceeding to the next step
- Relight the pilot light: Set the gas valve to “pilot,” hold down the reset button, and then light the pilot by holding a flame to the pilot burner. Keep holding the reset button for at least one minute before releasing it to make sure the pilot stays on.
- Turn the gas valve to “on”: If the pilot light remains on, turn the gas valve to “on,” and then replace the burner cover.
Common Issues With Pilot Light
Although these steps are straightforward, there are common challenges you may come across when checking and relighting your pilot light. Here are some of the issues you might experience and how to fix them:
- Clogged pilot orifice: A clogged pilot orifice may cause your pilot light to go out. Clean the orifice using a thin wire and some pressurized air.
- Faulty thermocouple: If the pilot light goes out soon after it’s relit, the thermocouple may be defective. Replace the faulty part.
- Low gas pressure: Poor gas pressure may cause the pilot light to flicker or refuse to light. Make sure the gas supply line is open, and the regulator valve is working correctly.
By checking your water heater’s pilot light, you can identify the problem and fix it quickly. Remember to follow all safety precautions and make sure your gas-valve is turned off before attempting to check pilot light.
Inspecting The Thermocouple
If you have a gas water heater, the thermocouple is a critical component that keeps your water heater running. The thermocouple is a heat sensor that detects the pilot flame. It sends a signal to the gas valve to allow gas to flow to the burner so that your water can heat.
If the thermocouple malfunctions, it can shut off the gas supply, causing the water heater to shut down completely. Here’s how to inspect the thermocouple to prevent this from happening:
Identifying A Faulty Thermocouple
Before we dive into how to inspect a thermocouple, let’s discuss how to identify a faulty one. Here are some visual cues that indicate your thermocouple needs replacement:
- The pilot light keeps going out
- The water doesn’t heat properly even though the pilot light is on
- You hear a clicking sound when you try to light the pilot
Inspecting And Replacing A Faulty Thermocouple
Inspecting and replacing the thermocouple is a simple process that requires minimal tools. Here’s what you should do:
- Turn off the power and gas supply to the water heater. This is essential to prevent any accidents during the inspection process.
- Remove the access panel located at the bottom of the water heater. This is where you’ll find the thermocouple. It’s the copper-colored wire that connects the gas valve to the pilot assembly.
- Disconnect the thermocouple from the gas valve. You should be able to do this using your hands, but if you can’t, you may need to use pliers.
- Remove the other end of the thermocouple from the pilot assembly.
- Inspect the thermocouple for any visible signs of damage or wear. If the thermocouple looks fine, you can clean it with a soft cloth and reattach it to the gas valve and pilot assembly.
- If the thermocouple is damaged or worn, you’ll need to replace it with a new one. You can find a replacement thermocouple at your local hardware store or online. Make sure to purchase the correct size and length to fit your water heater model.
- Install the new thermocouple by following the instructions provided with it. Make sure it’s securely attached to the gas valve and pilot assembly.
- Reattach the access panel and turn the gas and power supply back on.
By inspecting and replacing a faulty thermocouple, you’ll ensure your gas water heater runs smoothly and efficiently. Remember, if you’re uncomfortable performing any of these steps or you’re not sure what to do, it’s always best to seek help from a professional.
Checking The Gas Valve
When a water heater won’t stay lit, the gas valve could be the culprit. The gas valve is an essential component of the water heater’s heating process. It controls the flow of gas to the pilot and burner. If the valve becomes dirty, clogged, or faulty in any way, it could prevent the water heater from staying lit.
To check the gas valve, you need some basic tools and equipment, including a multimeter, adjustable wrench, and a flashlight. Follow these simple steps to inspect the gas valve:
- Turn off the gas and power supply to the water heater.
- Locate the gas valve on the water heater. It should be near the bottom of the tank or on the side.
- Use an adjustable wrench to remove the nut connecting the gas line to the valve.
- Carefully remove the valve from the water heater and check it for dirt or other debris.
- Check the valve for continuity using a multimeter. If the valve doesn’t have continuity, it may need to be replaced.
Some common issues that can arise with the gas valve include:
- A dirty valve: Gas valves can become dirty over time, leading to clogs in the valve’s tube. Clean the valve with a soft brush or compressed air to remove any debris.
- A faulty thermocouple: The thermocouple measures the temperature of the pilot flame. If it malfunctions, the gas valve may turn off the gas flow before the burner ignites. It may need to be replaced.
- A gas leak: If you smell gas at any point during the inspection, turn off the gas supply immediately. Contact a professional to address the problem.
When To Replace The Gas Valve
If the gas valve does not have continuity or you’ve tried cleaning it and other troubleshooting measures, it may be necessary to replace it. Installing a new gas valve requires a high skill level and should only be done by a professional.
Replacing the gas valve may be more expensive than attempting to fix the valve yourself. Still, it may be the only way to resolve the issue and prevent further problems with your water heater.
Addressing Other Possible Issues
When your water heater refuses to stay lit, it’s not always the thermocouple that’s the culprit. There are other potential causes that could lead to this issue. Here are some common issues that you must check:
- Faulty control valve: A faulty control valve can lead to a water heater not staying lit. This valve is responsible for regulating the gas flow, and if it’s not working correctly, the pilot light may go out.
- Clogged air intake: If your water heater’s air intake is clogged with debris, dust, or dirt, it may cause the pilot light to go out. A clogged air intake can also cause the water heater to shut down due to overheating.
Apart from these issues, there could be some other underlying reasons behind your water heater not staying lit. Keep reading to know how to identify these issues and what steps you can take to address them.
Finding The Causes
Before addressing any issue with your water heater, it’s important to find the exact cause. Here are some steps to follow to identify the root cause:
- Check the gas supply: Ensure that the gas supply valve near the water heater is open and not obstructed.
- Inspect the thermocouple: Check the thermocouple for any signs of damage, such as bends or chips.
- Clean the burner: Look for any signs of rust or corrosion in the burner assembly. A dirty burner can cause the pilot light to go out or result in flickering flames.
Taking Care Of The Issues
If you find that the cause of the problem is the control valve or clogged air intake, you can try resolving these issues yourself:
- For the control valve: You may be able to repair the control valve. Turn off the gas supply before removing the valve, then clean and check it for any debris or damage. If the valve is too damaged, it may need to be replaced.
- For the clogged air intake: Turn off the gas supply before cleaning the air intake with compressed air or a brush.
More Repair Options
If these steps didn’t work, or you’re unsure how to proceed, it’s crucial to seek help from a professional. Here are some additional repair options:
- Replace the thermocouple: If the issue was with the thermocouple, you may need to replace it.
- Replace the control valve: If the control valve is badly damaged, it cannot be repaired. It will have to be replaced to resolve the problem.
- Call a professional: If none of the above steps seem to work, it’s best to call a licensed plumber or hvac technician to help diagnose and repair the issue.
By following these steps, you should be able to identify and address the issues that cause a water heater to stop working properly. With the right care and maintenance, you’ll be able to keep your water heater running efficiently for years to come.
Frequently Asked Questions For How To Fix A Water Heater That Won’T Stay Lit
How Do I Know If My Water Heater Pilot Light Is Out?
Check the pilot light. If it’s off, try to relight it. If it won’t stay lit, the thermocouple might be faulty.
How Can I Fix A Faulty Thermocouple?
Firstly, shut off the gas supply and disconnect the thermocouple. Clean the end of the thermocouple and reconnect it. If that doesn’t work, it may need replacing.
What If The Burner Won’T Stay Lit?
If the burner won’t stay lit, there may be an issue with the gas supply, gas valve or burner. Check the gas supply, valves, and clean out the burner.
Can A Faulty Water Heater Be Dangerous?
Yes, a faulty water heater could lead to gas leaks, carbon monoxide poisoning, or a house fire, which can all be dangerous. It is essential to take immediate action and find a solution.
Should I Try To Fix My Water Heater Myself?
Diy water heater fixing can be dangerous and is not recommended. It’s essential to hire a professional plumber or technician to avoid any potential hazards and ensure the problem is adequately fixed.
Conclusion
To sum up, fixing a water heater that won’t stay lit can be a simple task if you know what to do. Firstly, make sure to understand the problem and diagnose it accordingly. Next, clean out the area around the pilot light and replace parts if necessary.
Be sure to follow manufacturer instructions carefully for safety purposes. Additionally, regular maintenance can prevent future problems and prolong the lifespan of your water heater. By taking the time to properly address any issues, you can save money on costly repairs or a replacement.
Now that you have the knowledge and tools to fix a water heater that won’t stay lit, you can have hot water flowing again in no time. Happy repairing!