A properly functioning hot water heater is essential for household comfort and routine. Whether it’s for a hot shower, washing dishes, or doing laundry, we rely on hot water daily. But what happens when your hot water heater pilot light keeps going out? This common issue can be frustrating and disruptive. Fortunately, understanding the causes and solutions can help you restore your hot water supply quickly.
This in-depth guide covers everything you need to know about why your hot water heater pilot light won’t stay lit, how to fix it, preventative maintenance tips, and when to call a professional. Let’s dive in.
What Is a Pilot Light and Why Is It Important?
The pilot light in a gas water heater is a small flame that stays lit to ignite the main burner whenever the thermostat signals the need for hot water. It’s essentially the ignition system for the heater. When the pilot light goes out, the burner won’t activate, and you’ll be left without hot water.
Most modern heaters have a safety mechanism to prevent gas from flowing when the pilot is out, which protects you from gas leaks. However, repeated issues with the pilot light could indicate an underlying malfunction that needs to be addressed.
Common Reasons Why the Pilot Light Keeps Going Out
1. Malfunctioning Thermocouple
The thermocouple is a safety device that detects the presence of the pilot flame. If the flame goes out, the thermocouple shuts off the gas valve to prevent leaks. However, if the thermocouple itself is faulty, it may misinterpret the pilot flame status and shut off the gas supply even when the flame is lit.
Signs of a Bad Thermocouple:
- The pilot light goes out shortly after being lit
- The flame appears weak or misaligned
Fix:
- Inspect the thermocouple for soot or corrosion.
- Use fine-grit sandpaper to clean it gently.
- Make sure it is positioned properly so it’s enveloped by the pilot flame.
- If cleaning and repositioning don’t work, replace it with a new one. Thermocouples are inexpensive and widely available at hardware stores.
2. Dirty or Clogged Pilot Tube
A dirty pilot tube can restrict the flow of gas, resulting in a weak flame or no flame at all. Dust, debris, or carbon buildup in the tube can block the gas from flowing freely.
Fix:
- Turn off the gas and let the heater cool.
- Remove the pilot tube and clear any obstruction using a needle or compressed air.
- Reassemble the components and relight the pilot light.
Cleaning the pilot tube regularly can prevent this issue from recurring.
3. Low Gas Pressure or Supply Issues
If there’s a problem with your gas supply, your pilot light won’t stay lit. This could be due to low pressure, an empty propane tank, or issues with the gas valve.
Fix:
- Confirm whether other gas appliances (like your stove or furnace) are functioning properly.
- If multiple appliances are affected, contact your gas utility provider.
- Check that the gas shut-off valve near the water heater is fully open.
- If using a propane tank, make sure it isn’t empty.
4. Drafts or Poor Ventilation
Strong air currents or poor ventilation can blow out the pilot flame. This is especially common in basements or garages with open windows, doors, or vents.
Fix:
- Identify and eliminate any drafts near the heater.
- Seal windows or install weather stripping.
- Install a draft shield around the pilot light assembly if necessary.
- Make sure the flue or vent stack is not obstructed.
5. Faulty Gas Control Valve
The gas control valve regulates the flow of gas to the pilot light and burner. A malfunctioning valve can intermittently cut off the gas supply, causing the pilot light to extinguish.
Fix:
- If all other parts are functioning correctly and the problem persists, the gas valve may need to be replaced.
- Because the gas valve is a critical component, replacement should be performed by a licensed technician.
6. Carbon Buildup or Soot Accumulation
Over time, soot and carbon deposits can accumulate around the pilot assembly. These deposits can block the pilot light or affect flame stability.
Fix:
- Turn off the heater and allow it to cool.
- Use a wire brush to remove any carbon deposits from the pilot and burner area.
- Clean the surrounding area to prevent debris from falling into the flame zone.
7. Age and General Wear of the Heater
Like any appliance, water heaters degrade over time. Components can corrode, weaken, or fail, especially if the unit is over a decade old.
Fix:
- If your heater is older than 10–15 years and consistently has problems, it may be time for a replacement.
- Upgrading to a modern, energy-efficient model can save you money and hassle in the long term.
Step-by-Step Guide to Relighting the Pilot Light
If the pilot light goes out, follow these general steps to relight it safely. (Always refer to your specific model’s instructions.)
- Turn the thermostat to the lowest setting.
- Turn the gas regulator valve to the “OFF” position and wait 5–10 minutes for gas to dissipate.
- Switch the valve to the “PILOT” position.
- Hold down the pilot button while igniting the pilot with a lighter or built-in igniter.
- Continue holding the button for 30–60 seconds after the flame is lit.
- Release the button and turn the valve to the “ON” position.
- Turn up the thermostat and ensure the burner ignites.
If the pilot light won’t stay lit, proceed to the troubleshooting steps above.
Preventative Maintenance Tips
Preventing pilot light issues before they start is the best strategy for ensuring consistent hot water. Here’s how:
1. Annual Professional Inspection
Have your water heater inspected annually by a licensed technician. They can clean the components, check gas pressure, and test safety mechanisms.
2. Clean the Pilot Assembly
Make it a habit to inspect and clean the pilot assembly at least once per year.
3. Monitor Ventilation
Ensure that your water heater is properly ventilated and away from open drafts. This also protects against carbon monoxide buildup.
4. Check for Leaks or Corrosion
Periodically inspect the heater for rust, corrosion, or any leaks around the base. These are signs of aging and potential failure.
5. Flush the Tank Regularly
Sediment can build up in the tank and affect performance. Flush your tank at least once a year to remove mineral deposits.
When to Replace Your Water Heater
If you’re repeatedly dealing with pilot light issues and your water heater is over a decade old, replacing the unit may be more cost-effective in the long run.
Signs It’s Time to Replace:
- Frequent pilot light outages
- Rust-colored water
- Rising energy bills
- Leaks around the base of the heater
- Inconsistent water temperature
When to Call a Professional Plumber or Technician
While some pilot light problems are easy to fix, others can pose safety risks or require specialized tools and knowledge.
Call a Pro If:
- You suspect a gas leak (smell of rotten eggs)
- The gas control valve needs replacement
- Cleaning and relighting don’t resolve the issue
- You’re uncomfortable working with gas appliances
Licensed professionals can quickly diagnose and resolve issues while ensuring your safety.
Safety Considerations
- Never attempt repairs while the gas is on.
- Don’t force components; you could damage the unit.
- If you ever smell gas, evacuate the area and contact your gas company or fire department immediately.
Final Thoughts
A pilot light that keeps going out isn’t just annoying—it can be a sign of a larger issue with your water heater. From a simple dirty pilot tube to a failing thermocouple or gas valve, many problems can be resolved with basic tools and a bit of knowledge.
However, safety is key. If you’re ever unsure, call a licensed plumber or technician. Maintaining your water heater through regular inspections and cleanings can also prevent these problems from occurring in the first place.
A little maintenance now can save you from cold showers and costly repairs down the road.
Frequently Asked Questions (FAQs)
1. Can I relight the pilot light myself?
Yes, you can usually relight the pilot light by following the instructions on the water heater’s label. Make sure to wait 5–10 minutes after turning off the gas to avoid ignition of leftover gas.
2. What causes the pilot light to go out repeatedly?
Common causes include a dirty thermocouple, clogged pilot tube, drafts, gas supply issues, or a faulty gas control valve.
3. How much does it cost to replace a thermocouple?
Most thermocouples cost between $10 and $20. If you hire a professional, expect to pay around $75–$150 for parts and labor.
4. How do I know if the gas control valve is bad?
If all other components work fine but the pilot light still won’t stay lit, the valve might be faulty. A technician can test and confirm this.
5. How often should I service my water heater?
Professional servicing once a year is ideal. In between, perform basic maintenance like flushing the tank and cleaning the pilot assembly.
6. Is it dangerous to keep trying to light a faulty pilot?
Yes. Repeated unsuccessful attempts to light the pilot can lead to gas buildup. Always allow time for gas to dissipate and follow safety instructions.
Need help with your water heater? Don’t suffer through another cold shower—take action today. Troubleshoot the issue or reach out to a professional for a quick, safe fix!