Why Does My Water Heater Pilot Light Keep Going Out?: 1 Minute to Understand Common Causes and Solutions

If you’ve noticed your water heater pilot light keeps going out, it can be both frustrating and disruptive—especially when it leads to cold showers and unreliable hot water. There are several reasons this may happen, most of which are easy to diagnose, though some do require a professional touch. Common causes include a faulty thermocouple, dirty pilot tube, issues with the gas supply, or ventilation problems. In older water heaters, components tend to accumulate dust, grime, or suffer wear, making the system less efficient over time.

The most frequent culprit is a malfunctioning thermocouple—a safety device that senses when the pilot is lit and allows gas to flow. If the thermocouple gets dirty or bent out of position, it may mistakenly signal the gas valve to shut off gas flow, extinguishing the pilot light. Clogged pilot tubes from soot or debris can also hinder the steady gas flow required for the flame. Other possibilities include drafts from poor ventilation, insufficient or fluctuating gas pressure, or even a defective gas control valve. In rare cases, the entire system may need an upgrade.

As a designer, whenever I face issues like this—in rental properties or remodels—I also think about efficiency and safety as crucial elements of a comfortable and functional home. When recurring pilot light issues hint at aging infrastructure, sometimes the best solution isn’t just repair, but a thoughtful upgrade. For homeowners and professionals, using planning tools such as Home Designer can help map out mechanical placements and safety features, ensuring that everything, from venting to utility access, is designed for sustainability and minimal hassle in the years ahead.

Tips 1:

Regularly inspect and clean your water heater’s pilot assembly and surrounding area to prevent dust and debris accumulation. If the problem persists after basic troubleshooting, consult a professional to check for gas line or thermocouple issues. Consider the age of your system—sometimes it’s more cost-effective to replace an outdated unit than pursue ongoing repairs.

FAQ

Q: What is a thermocouple and how does it affect my pilot light?

A: The thermocouple is a safety device that detects if the pilot flame is lit. If it’s dirty or damaged, it may shut off gas flow, causing the pilot to go out.

Q: Can a draft cause my water heater pilot light to turn off?

A: Yes, drafts or improper ventilation near your water heater can blow out the pilot light, especially if the heater is located in a breezy area or close to vents.

Q: How do I know if the gas control valve is failing?

A: If you’ve cleaned and adjusted the pilot and thermocouple but the pilot still won’t stay lit, the gas control valve may be defective and require replacement by a professional.

Q: Is it safe to relight the pilot light myself?

A: Relighting can be safe if you follow manufacturer instructions, but if you smell gas or if issues persist, consult a qualified technician for safety.

Q: When should I replace my water heater instead of repairing it?

A: If your water heater is over 10-15 years old and repeatedly has pilot or other issues, replacing it may offer better long-term reliability, efficiency, and safety.