How to Light a Water Heater Pilot

A homeowner guide from Drain Edge Rooter, a licensed plumbing company in Rialto, CA (C-36 #1078977). Open 24/7, call anytime: (909) 927-3194.

Safety first: if you smell gas, do not light anything, do not touch light switches or electrical devices, and do not try to find the leak. Leave the home right away, then call SoCalGas or 911 from outside. Always follow the instructions on the label on your water heater, and call a licensed plumber if you are unsure about any step.

If you suddenly have no hot water and you have a gas tank water heater, the pilot light may have gone out. Many water heaters can be relit by the homeowner by following the instructions on the label. This guide explains the general process for standard and push-button models and why a pilot might not stay lit. Your unit's label is the final word; follow it exactly.

Before you begin

• Smell for gas first. If you smell gas, stop. Do not light anything. Leave the home and call SoCalGas or 911 from outside.
• Read the lighting label on the front of the tank. It shows the steps and wait times for your model.
• Make sure the gas supply valve on the pipe to the heater is open (lever parallel to the pipe).
• Check that the tank is full. Never light a heater with an empty tank.
• Keep flammables away from the heater, including gasoline, paint thinner and cleaning products.

Is it a standing pilot or electronic ignition?

Most traditional gas tank water heaters have a standing pilot: a small flame that stays lit and ignites the main burner when the water needs heating. Many power-vent and newer high-efficiency units use electronic ignition and have no pilot to light. If your unit has a power cord, a blower fan, or a display with error codes, follow the label and manufacturer instructions for resetting it rather than trying to light a pilot.

Standard models: lighting with a long lighter

Some older units require lighting the pilot with a long lighter or match. The general steps:

1. Turn the gas control knob to OFF and wait the time listed on the label (often several minutes) so any gas can clear.
2. Remove the outer access cover and, if present, the inner cover to reach the pilot. Many newer units have a sealed combustion chamber and cannot be lit this way.
3. Turn the knob to PILOT.
4. Press and hold the knob or the separate pilot button to send gas to the pilot.
5. While holding it down, light the pilot with a long lighter at the pilot burner.
6. Keep holding the button for the time the label says (often around a minute) after the pilot lights, so the thermocouple heats up.
7. Release slowly. The pilot should stay lit.
8. Replace the covers, then turn the knob to ON and set the temperature.

Push-button piezo igniter models

Most newer standing-pilot heaters have a sealed burner chamber and a piezo igniter, a button that makes a click and spark.

1. Turn the gas control knob to OFF and wait the time on the label.
2. Turn the knob to PILOT.
3. Press and hold the pilot button.
4. While holding it, press the igniter button repeatedly until you see the pilot flame through the sight glass.
5. Keep holding the pilot button for the time listed on the label after it lights.
6. Release slowly and confirm the pilot stays lit in the sight glass.
7. Turn the knob to ON and set the temperature. The main burner should come on if the water needs heating.

Do not remove the sealed chamber cover on these units to light the pilot by hand.

Why a pilot will not stay lit

• Thermocouple or thermopile: this is the most common cause. The thermocouple is a small sensor that sits in the pilot flame. When it is hot, it tells the gas valve it is safe to keep gas flowing. If it is worn, dirty, loose or not positioned in the flame, the gas valve shuts off as soon as you release the button.
• Dirty or weak pilot flame: a clogged pilot orifice or dust in the burner can make the flame too small to heat the thermocouple.
• Flammable vapor sensor: many newer heaters have a safety sensor that shuts the unit down if it detects vapors or lint buildup on the air intake screen. Some must be serviced or reset by a professional once it trips.
• Draft or venting problems: a blocked vent or strong draft can blow out the pilot or trigger safety shutoffs.
• Gas supply issues: a partly closed supply valve or a problem with the gas line.
• Faulty gas control valve.

What not to do

• Do not keep relighting a pilot over and over if it will not stay lit.
• Do not bypass, tape down or disable any safety device.
• Do not light the pilot if you smell gas.
• Do not remove a sealed combustion chamber cover.

When to call a pro

Call a licensed plumber if the pilot will not light, goes out after you release the button, keeps going out over time, the flame is yellow or lazy instead of mostly blue, you see soot or scorch marks, or a safety sensor has tripped. These usually point to a thermocouple, burner, venting or gas valve problem. Drain Edge Rooter is open 24/7, so call anytime at (909) 927-3194. If you smell gas, leave first and call SoCalGas or 911.

Related services and areas

Related services: Water Heater Repair & Installation, Water Heater Repair in Rialto, Gas Line Repair. We serve the whole Inland Empire, including plumber in Rancho Cucamonga, plumber in Redlands, plumber in Highland, plumber in San Bernardino. Also see How to Flush a Tank Water Heater and all homeowner plumbing guides.

Need help?

Drain Edge Rooter is open 24/7, so call anytime at (909) 927-3194. We will talk through the problem and give you a straight answer on timing.