How to Light a Pilot Light on a Water Heater

How to Light a Pilot Light on a Water Heater

Relighting a water heater pilot light is a straightforward task you can usually handle yourself with a few minutes and a long match or lighter. The process is similar across most gas water heaters, but the exact sequence depends on whether your unit has an automatic igniter or a standing pilot. Start by checking for a gas smell; if you detect one, do not proceed and call your gas utility or a technician immediately.

Gather What You Need

• A long-reach lighter or match
• The water heater owner's manual (if available)

Most modern water heaters label the pilot light assembly with a small diagram. If yours does not, look for a red or black knob on the gas valve near the bottom of the tank, typically marked Off, Pilot, and On.

Step-by-Step Relighting Process

Some models have a piezo spark igniter; in that case, you press the spark button repeatedly while the knob is in Pilot until the light catches, then hold the knob for the same waiting period.

Troubleshooting When the Pilot Won't Stay Lit

If the pilot goes out as soon as you release the knob, the thermocouple may be dirty or misaligned. The thermocouple is a small safety sensor that shuts off gas when no flame is present. Try gently cleaning the tip with fine sandpaper or repositioning it so the flame fully envelops it. A weak pilot flame can also indicate low gas pressure, a partially closed gas valve, or a faulty thermocouple that needs replacement.

When to Call a Professional

Call a licensed plumber or gas technician if you smell gas throughout the process, if the pilot refuses to light after several attempts, or if the water heater is older and the gas valve shows signs of wear. A professional can also check the combustion chamber for cracks and verify proper ventilation, which is especially important in enclosed utility spaces.