Blog #11: Why Your Water Heater Pilot Light Keeps Going Out (and How to Fix It Safely)
Carmel • Westfield • Indianapolis • Hamilton County
If your gas water heater keeps going cold and you find yourself relighting the pilot over and over again, you’re not alone. Pilot light issues are among the most common complaints we handle at ExpertPipe Indy, especially in older water heaters around Carmel, Westfield, Noblesville, and Indianapolis.
The good news? It’s usually fixable — and it’s a clear sign that your water heater needs attention before a bigger failure happens. Let’s break down the causes, the safe fixes, and when it’s time to replace your water heater altogether.
1. Understanding How the Pilot Light Works
The pilot light is a small flame that ignites the burner whenever the water temperature drops below your thermostat setting. If the pilot goes out, the burner won’t light — meaning no hot water.
Most gas heaters rely on three key components:
Thermocouple (or flame sensor) – detects if the flame is burning.
Gas control valve – regulates gas flow.
Pilot assembly and orifice – keeps a small flame lit continuously.
When any of these parts malfunction or get dirty, the pilot light becomes unstable and goes out.
2. The Most Common Causes of Pilot Light Failure
A. Dirty or Clogged Pilot Orifice
Dust, rust flakes, or debris inside the pilot opening restrict the flame and prevent it from staying lit.
Fix:
Turn off the gas supply, remove the pilot tube, and clean the tip with compressed air or a fine wire. If it still flickers, the orifice may need replacement.
Pro tip: Carmel basements with high humidity or rust-prone conditions accelerate this problem.
B. Failing Thermocouple
The thermocouple senses heat from the flame and signals the gas valve to stay open. When it’s weak, bent, or dirty, the gas supply cuts off even if the flame is burning.
Fix:
Replace the thermocouple (a $20 part, $120–$150 total service cost). We test the millivolt output to confirm it’s faulty before replacement.
C. Drafts or Poor Ventilation
If your water heater sits near a garage door, vent, or basement window, wind can blow out the pilot. Improper venting can also pull the flame off the thermocouple.
Fix:
Install a vent hood, seal gaps, or correct vent pipe slope (must rise at least ¼ inch per foot). We’ll check the draft direction using a smoke test to confirm.
D. Faulty Gas Control Valve
If the control valve isn’t responding properly, it may cut gas supply even when the thermocouple works fine. This is less common but potentially dangerous.
Fix:
Replace the control valve assembly ($200–$350). Always done by a licensed plumber — never DIY with gas components.
E. Moisture or Corrosion Inside the Burner Chamber
Leaks or high humidity can cause rust or condensation near the pilot, disrupting the flame.
Fix:
Dry and clean the area, check for active leaks, and replace corroded fittings. If the tank is leaking, replacement is mandatory.
F. Age and Wear
If your water heater is over 10 years old, pilot problems are usually the first sign of overall decline — corroded components, worn seals, and declining burner performance.
Fix:
At that stage, replacing the unit saves more in the long run than repeated repairs.
3. How to Relight Your Pilot Safely
⚠️ Caution: If you smell gas, stop immediately. Turn off the gas supply and call a professional or your gas utility company.
Step-by-step:
Turn the control knob to OFF and wait 5–10 minutes for gas to clear.
Locate the pilot knob and igniter button (or long lighter).
Turn the knob to PILOT and press it down to start gas flow.
While holding it, press the igniter until the pilot lights.
Keep holding the knob for 30 seconds, then release.
Turn the knob to ON and listen for the main burner to ignite.
If the flame won’t stay lit after two attempts, do not keep trying — call ExpertPipe Indy to inspect it safely.
4. When It’s Time to Replace the Unit
If your pilot continues to go out even after replacing the thermocouple and cleaning the orifice, the issue often lies deeper in the gas valve or tank condition.
Here’s when replacement is smarter than repair:
SymptomLikely CauseRecommendationPilot light won’t stay lit after repairFailing gas control valveReplace water heaterRust or moisture around baseTank corrosionReplaceAge over 10 yearsInternal wearReplaceRepeated service calls in 6 monthsSystem fatigueReplace
New Bradford White or Rheem models include electronic ignition — no standing pilot needed. They’re more efficient and safer overall.
5. How ExpertPipe Indy Handles Pilot Light Calls
When you call (317) 731-3028, here’s what we do:
Visual inspection of the pilot, thermocouple, and burner.
Draft test for negative pressure or vent backflow.
Electrical and gas safety test.
Millivolt output test on the thermocouple.
Cleaning and reassembly.
Full combustion check to ensure safe operation.
If your heater is beyond repair, we’ll provide same-day replacement options, including high-efficiency gas or tankless systems.
6. Prevention Tips
Keep the burner area clean and dry.
Avoid storing paint cans or chemicals near the water heater — fumes corrode components.
Schedule annual tune-ups to clean the pilot assembly.
Check venting during windy seasons to prevent downdrafts.
Consider upgrading to an electronic ignition water heater next time.
7. FAQ — Pilot Light Problems
Q: Why does my pilot light go out overnight?
A: Usually a weak thermocouple or draft issue. We can fix that same-day.
Q: Can I keep relighting it myself?
A: You can once or twice, but if it keeps going out, there’s a safety or gas issue that needs attention.
Q: Is it dangerous if my pilot keeps going out?
A: Yes — constant relighting without proper testing risks gas buildup or carbon monoxide leaks.
Q: How much does a pilot light repair cost?
A: $120–$350 depending on whether the thermocouple or valve needs replacement.
Q: Can you replace my water heater the same day?
A: Absolutely. ExpertPipe Indy offers same-day replacements across Hamilton County and surrounding areas.
📞 Call ExpertPipe Indy at (317) 731-3028
🌐 Visit expertpipeindy.com
ExpertPipe Indy — Keeping Carmel, Westfield, and Indianapolis homes safe, warm, and worry-free since day one.
