The pilot light on your water heater may not ignite due to a faulty thermocouple, gas supply issues, or a clogged pilot tube; check these components first.
A gas water heater’s pilot light is essential for heating your home’s water. When it won’t stay lit, you’re left with cold showers and frustration. Understanding the root causes can help you troubleshoot or decide when to call a professional.
Common Causes of Pilot Light Failure
1. Faulty Thermocouple
The thermocouple is a safety device that detects the pilot flame. If it fails, it shuts off gas flow to prevent leaks. Signs include:
- Pilot lights but won’t stay lit
- Visible corrosion or damage
- Age (most last 5-10 years)
Replacement typically costs $150-$400. For DIYers, quality pilot assemblies are available.
2. Gas Supply Issues
Insufficient gas pressure prevents ignition. Check:
- Main gas valve position (should be fully open)
- Gas meter for restrictions
- Other gas appliances for proper operation
According to U.S. Department of Energy, gas water heaters require proper ventilation and gas pressure between 3.5-10.5 inches water column.
3. Clogged Pilot Tube
Dirt, dust or spider webs can block the tiny orifice. To clean:
| Step | Action |
|---|---|
| 1 | Turn off gas supply |
| 2 | Use compressed air or a needle |
| 3 | Reassemble and test |
Advanced Troubleshooting
Draft Problems
Strong drafts can extinguish pilot lights. Ensure:
- Vent pipes are properly connected
- No nearby fans or windows creating cross-breezes
- Draft hood is correctly installed
Faulty Gas Control Valve
This complex component regulates gas flow. Symptoms include:
- Pilot won’t light despite good gas supply
- Irregular flame patterns
- Gas odor when attempting to light
Valve replacement often requires professional help due to gas line connections.
When to Call a Professional
Seek expert help for:
- Persistent gas odors
- Visible soot or blackening
- Water leaks near burner assembly
- Older units (10+ years) needing frequent repairs
For modern replacements, consider high-efficiency models that may eliminate pilot light issues entirely.
Safety First
The Consumer Product Safety Commission warns that improper gas appliance repairs cause hundreds of injuries annually. If unsure, always consult a licensed technician.
