Gas water heaters can suddenly stop working when their pilot light fails to ignite, leaving your home without hot water. Many homeowners face this common issue unexpectedly. You can resolve this problem yourself by following simple safety precautions.
Your pilot light issues might stem from a faulty thermocouple, a clogged pilot orifice, or problems with the gas supply. We’ll walk you through each troubleshooting step in this piece to help you get your hot water flowing again. You’ll discover how to pinpoint the exact cause and safely complete the repairs.
Understand Common Pilot Light Issues
A water heater’s pilot light might not stay lit due to several underlying causes. Three problems typically create this situation.
A dirty pilot orifice blocks the gas flow to the pilot light. The pilot orifice’s small opening allows gas to flow and create the pilot flame. Dirt and debris in this opening restrict gas flow and create a weak or yellow flame instead of the proper blue cone shape. This weak flame can’t maintain operation or heat the thermocouple.
The thermocouple is a vital safety device in gas water heaters. This copper rod’s position near the pilot flame helps control the heater’s gas flow. The thermocouple’s common problems include:
- The sensor’s accumulated soot or debris
- Poor alignment with the pilot flame
- Age-related wear and tear
- Manufacturing defects
The thermocouple automatically cuts off the gas supply to prevent leaks and potential risks if it fails.
Ventilation problems and drafts can extinguish the pilot light. Water heaters need the right amount of airflow to work. Insufficient or excessive air creates several problems. Poor ventilation leads to:
- Carbon monoxide buildup in enclosed spaces
- Strong drafts that extinguish the pilot light
- Combustion gasses that flow backward
- Lack of oxygen for proper combustion
The water heater’s safe operation depends on proper ventilation. Enclosed spaces need adequate air supply and proper exhaust venting to ensure safe and reliable operation.
Perform Basic Troubleshooting
Simple water heater pilot light troubleshooting needs careful attention to safety and proper procedures. You can resolve common pilot light problems safely by following the right steps.
Turn off the gas and wait
Safety comes first when working with gas appliances. You should locate the gas control valve and turn it to the “OFF” position. Taking a 5-10 minute break at this point is significant. This break allows any accumulated gas to clear out and keeps everyone safe.
Inspect the pilot light assembly
A good look at your pilot light can show potential issues quickly. Your pilot light should have these key features:
- A strong blue flame that never turns yellow or flickers
- A steady and even burning pattern
- A pilot tube without any blockage
- A clean thermocouple free of debris
The pilot tube might need cleaning with a dry cloth and fine sandpaper if it looks dirty. You must handle all components with care during the cleaning process to avoid damage.
Try relighting the pilot
Homeowners can relight the pilot light after a thorough inspection. The gas knob should be turned to the “pilot” position. Press and hold down the knob completely. The pilot light can be ignited with the igniter button or a long lighter. The knob must be held down for about 30 seconds after the pilot lights up.
The pilot might go out once you release the knob. You should wait a few minutes before trying again. Multiple attempts might be needed. If the pilot won’t stay lit after three attempts, this indicates a more serious issue and professional help will be needed.
The flame should be monitored carefully throughout the relighting process. A properly functioning pilot light shows a steady blue flame and maintains consistent size. The pilot light’s unusual behavior or inability to stay lit might point to thermocouple issues or problems with the gas supply that need expert evaluation.
Address Thermocouple Problems
A thermocouple serves a vital role in water heater safety and operation. This small device costs between $5-$10 and its malfunction often leads to pilot light problems.
Test the thermocouple
A multimeter set to millivolts helps you test a thermocouple effectively. The testing process is straightforward.
Your multimeter should be on millivolts DC setting. Place one probe on the copper part and connect the second probe to the gas valve. The pilot button needs to stay pressed down during the test. The reading should exceed 25 millivolts.
Important: A reading below 15 millivolts signals a faulty thermocouple that requires replacement.
Clean or replace the thermocouple
You can restore a dirty thermocouple with proper cleaning. Fine-grit emery cloth or steel wool works well to remove soot and debris from the tip. The thermocouple needs careful detachment from the burner assembly to get a full picture of the cleaning needs.
The thermocouple might need replacement if cleaning doesn’t fix the issue. Turn off the gas supply before attempting replacement. The process requires removing three nuts that connect the thermocouple to the gas valve. Most burner assemblies slide out easily and give access to remove the old thermocouple.
Ensure proper thermocouple positioning
Proper positioning plays a vital role in operation. The thermocouple’s tip must rest directly in the pilot flame. Incorrect placement can stop the pilot light from staying lit, even with a new thermocouple. The component might get damaged if connections are overtightened during installation.
A clean thermocouple tip should not have white, chalky deposits. The component’s life extends with maintenance checks every six months to prevent buildup. Replacement offers the best solution for water heaters that are over 10 years old and face frequent pilot light problems.
Resolve Gas Supply and Pressure Issues
Problems with gas supply can stop your water heater’s pilot light from working right. You need to check three key areas to understand and fix these issues.
Check for gas line blockages
Debris, water, and tree root intrusion often block gas lines. Several signs indicate a blocked gas line in your home:
- Gas appliances produce low flames
- Hot water remains insufficient even with high temperature settings
- Gas flows to some appliances while others receive none
Important Safety Note: A blocked gas line can create dangerous pressure and cause pipes to burst. You should turn off the main gas connection right away and call a licensed plumber when you suspect a blockage.
Verify proper gas pressure
Your water heater needs the right gas pressure to work correctly. Gas water heaters must meet these standard requirements:
- Maximum inlet pressure: 14.0″ water column (w.c.)
- Minimum line pressure: 1.0″ w.c. above operating manifold pressure
- Natural gas manifold pressure: 4.0 ±0.5″ w.c.
- Propane gas manifold pressure: 10.0 ±0.5″ w.c.
Gas pressure below these specifications can cause pilot light issues and reduce heating performance. A technician can measure the pressure with a manometer to verify proper readings. The gas company should adjust the pressure when readings don’t match these specifications.
Inspect the gas control valve
A gas control valve manages the gas flow that reaches your water heater. Your pilot light may not work properly if the valve malfunctions. Regular testing helps ensure safe operation.
Conclusion
FAQs
What should I do if my water heater’s pilot light won’t ignite? To light the pilot on your water heater, press and hold the gas knob down. While holding it, use a long lighter to ignite the pilot, or press the igniter button if your heater has one. Once the pilot is lit, release the knob and turn it to the “On” position. Listen for the main burner to activate.
What steps should I take if the pilot light on my water heater fails to relight? First, turn the gas valve to the ‘off’ position and wait for at least three minutes. After waiting, turn the valve to the ‘pilot’ setting. Use a lit match to ignite the pilot while pressing the reset button on the pilot control.
How can I tell if the thermocouple on my water heater is malfunctioning? A faulty thermocouple might be the issue if the pilot flame lights but extinguishes when you release the gas control knob. Alternatively, if the gas is on but the pilot won’t light, the pilot tube may be blocked. Remove the pilot tube from the gas valve and use compressed air to clear any obstructions.
Why isn’t my gas pilot light staying lit? A common reason for a pilot light that won’t stay lit is a dirty or defective thermocouple. Try cleaning the thermocouple to remove any dust buildup. If the pilot light still fails to stay lit after cleaning, you may need to replace the thermocouple.
I’ve tried repeatedly to light my water heater with a Honeywell controller but it won’t ignite. What should I do? If you’ve attempted to light your water heater multiple times without success, especially after draining your water lines or noticing sediment in the tank, it might be helpful to thoroughly clean or replace parts affected by sediment buildup, such as the pilot assembly or the gas valve. Ensure there are no gas supply issues and consider consulting a professional if the problem persists.