HVAC Guide: How to Light a Water Heater with Electronic Pilot

This guide explains in detail how to light a water heater with electronic pilot when starting a new unit or restarting one after repairs or service.

If you’re unsure what type water heater you have, the Tools & Specs to Keep in Mind section will assist you in determining if your water heater has an electronic pilot. There are tips for keeping you safe when working with gas too.

Why You Might Need to Light a Water Heater

The pilot needs to be lit when:

A newly installed unit is first started;
The gas has been shut off for repair or service;
The water heater stops heating for no apparent reason.

If the last scenario occurs, check that the gas valve handle is parallel to the gas line to indicate it is in the on position. Then, look for a small blue pilot flame in the small window at the bottom of the heater.

If there is no flame and the gas is on, the steps below describe how to light a water heater with electronic pilot. If the pilot is on and the dial is set to hot or one of the hotter settings but the unit still isn’t firing to make hot water, your problem is more likely the gas valve, thermocouple or thermostat and should be diagnosed by a professional.

Tools & Specs to Keep in Mind

Water heaters are fired in one of three ways. So, knowing the type you have is essential to lighting it:

Standing pilot, electronically lit: Many newer water heaters require that you know how to light a water heater with electronic pilot. They have a gas control that looks like this one made by Honeywell. Look for a status light that blinks when the pilot is lit and a small igniter button, possibly with a lightning bolt symbol next to it.
Standing pilot, manually lit: If your water heater is quite old, it might not have an electronic pilot. There will be no status light or ignition button. We recommend you contact an HVAC company that repairs old water heaters for information on manually lighting the pilot or to discuss replacing the water heater.
Electronic ignition without a pilot: Some newer units don’t have standing pilot light, that is, one that is always lit. They fire only when water heating is ncessary. Clues that you have one of these models are that it is newer and does not have an ignition button. If the unit isn’t lighting, it is probably a faulty thermocouple or gas control valve.

How to Light a Water Heater with Electronic Pilot in 6 Steps

If you’re sure your water heater has an electronic pilot (type 1 above), locate its gas control assembly. It is a box attached near the bottom of the unit with a rotating control knob or dial, igniter button, status window, wiring and the gas line attached.

Here are step-by-step instructions for how to light a water heater with electronic pilot:

If the water heater has electrical wiring for a fan or other function, then make sure its circuit is on;
Turn the gas valve to the on position, if necessary;
Rotate the gas-control knob or dial to the pilot position;
Depress the knob. Then, hold it down while completing the next step;
Press the ignition button about once per second. Take this action until you see the status light begin to blink every few seconds. This indicates that the pilot is lit. The process that takes up to 60 seconds in a newly installed unit;
Once the pilot is lit (its blue flame can be seen through the small observation window), turn the knob to the hot position or a hotter setting, if you prefer. Then, listen or look for the gas burner to fire.

If the burner stays lit, you know how to light a water heater with electronic pilot!

Bonus Tips

If the water heater doesn’t fire, there are two more tips that might solve the problem.

Sometimes, the pilot will go out before you can turn the knob to one of the water temperature settings. This is because the thermocouple hasn’t heated sufficiently. If that happens, wait 10 seconds before adjusting the knob from pilot to a temperature setting.
If repeated attempts to light the pilot and water heater fail, look for a small reset button at the base of the unit with wiring to it. Also, if your water heater has one, press and hold it for five seconds. Then, retry the process.

Caution Notes

Never try to light an electronic pilot with mechanical means such as a match or barbecue lighter. If you can’t get an electronic pilot lighted using the steps below, the control assembly might have to be replaced before attempting to use the appliance.

Before starting any gas appliance, check the gas connection to make sure it tight. NEVER check for a gas leak with a flame. Mix a few drops of water with a few drops of liquid dish detergent, and apply the solution to the gas connection. View the connection from all angles. Bubbles in the solution indicate a gas leak. If bubbles develop, tighten the connection, and test it again. Also, check to ensure that the installer wrapped the pipe with gas-sealing PTFE tape, which is very thin and yellow. If you don’t see it, turn off the gas, disconnect the line and add the tape before reconnecting and testing the line.

If a gas leak persists, turn off the gas, air out the space and call an HVAC professional for assistance.

Join the Conversation

Hopefully your unit is running now, creating the hot water you need.

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Image from depositphotos.com.