The pilot light on a gas water heater is a small flame that ignites the burner to heat water. Knowing how to safely light the pilot can save time and prevent unnecessary service calls. This guide covers standing-pilot and electronic-ignition models, common safety concerns, and step-by-step instructions to light the pilot, along with troubleshooting tips for non-ignition issues.

Safety First And Why It Matters

Gas appliances can pose risks if not handled correctly. Before attempting to light the pilot, ensure the area is well-ventilated and free from flammable materials. If you smell gas (a rotten egg odor), evacuate immediately and call your gas utility or emergency services. Always read the manufacturer’s manual for model-specific instructions. If the control knob is difficult to operate or you suspect a gas leak, contact a licensed technician.

Identify Your Water Heater Type

Water heaters typically use one of two ignition systems: standing-pilot and electronic-ignition. Standing-pilot models have a small flame that stays lit continuously, while electronic-ignition models spark or glow to light the burner only when hot water is needed. Understanding your type helps determine the correct procedure and safety steps.

Tools And Preparations

Gather these items before you begin: flashlight, soapy water or a spray bottle for leaks, a dry cloth, and the user manual. You may also need a screwdriver to access the access panel on some units. Have a source of ventilation and a clear workspace. For standing-pilot units, you’ll use the control knob and a match or lighter. For electronic-ignition units, you’ll rely on the control knob and the on-board ignition sequence.

Lighting The Standing-Pilot Water Heater

Standing-pilot heaters require manually lighting the pilot flame. Follow these steps carefully to minimize risk and ensure a successful ignition.

Turn gas control knob to OFF and wait at least 5 minutes to clear any gas buildup.
Set the control knob to PILOT and press and hold the reset button (or knob) to engage the gas valve.
While holding, use a long-stemmed lighter or a lit match to ignite the pilot flame at the pilot assembly. Keep the flame near the pilot opening for about 15–30 seconds if the burner doesn’t ignite immediately.
Release the reset button slowly while continuing to hold the knob in the PILOT position for another 1–2 minutes to allow the thermocouple to heat up and confirm a stable flame.
If the pilot stays lit, turn the knob to ON or AIR and HEAT as indicated by the model’s labeling. Adjust the thermostat to your desired hot water temperature.
If the pilot goes out, turn to OFF, wait 5 minutes, and repeat steps 1–3. If ignition fails after multiple attempts, do not keep trying; contact a professional.

Note: Always keep the area around the burner clean and free of dust. If you notice soot or a yellowish flame, the burner may be dirty or the gas-air mix may be off—shut off the unit and consult a technician.

Lighting An Electronic-Ignition Water Heater

Electronic-ignition models light the burner automatically when hot water is requested. They eliminate the standing flame but still require basic checks if cold water is the issue.

Set the thermostat to a mid-range temperature (120–130°F) to balance comfort and energy use.
Make sure the unit is receiving power if it uses an electronic control panel. Check for tripped circuit breakers and check the power switch if present.
Turn the thermostat knob to the Gas On position and request hot water. The ignition sequence will activate, and the burner should light within a few seconds.
If no flame ignites within 30 seconds, turn the knob to OFF, wait 5 minutes, and retry. If it still fails, inspect for gas supply issues or faulty igniters and contact a licensed professional.

Common Troubleshooting For A Non-Lighting Pilot

When the pilot won’t light, several issues could be at play. Approach each with safety in mind and avoid making risky adjustments.

Gas supply problems: Ensure the gas valve is fully open. If you use propane, confirm the tank isn’t empty. If you suspect a supply issue, contact your gas utility or a professional.
Thermocouple failure: A faulty thermocouple may prevent the pilot from staying lit. Signs include a pilot that lights briefly and then goes out. A technician can test and replace the thermocouple if needed.
Dirty burners or orifices: Soot or debris can disrupt flame quality. A professional cleaning can restore proper combustion.
Ventilation problems: Poor venting can cause backdrafts or flame instability. Check for obstructions and ensure proper vent routing according to the manual.
Control valve issues: A malfunctioning control valve may prevent ignition. Replacements require a licensed technician.

Gas Odor, Leaks, And Immediate Actions

If you smell gas, evacuate immediately and call your gas provider or emergency services. Do not operate electrical switches, use a phone indoors, or attempt to light a flame. After ensuring safety, a technician should inspect sealed connections, gas lines, and the pilot assembly for leaks.

Maintenance Tips To Prevent Ignition Problems

Regular maintenance can extend the life of a water heater and improve ignition reliability. Consider these actionable practices.

Schedule annual professional inspections to check the burner, thermocouple, gas valve, and venting system.
Inspect for corrosion or mineral buildup in the burner and pilot areas; clean as directed by the manufacturer.
Test the pressure relief valve and drain the tank periodically to remove sediment that can affect heating efficiency.
Keep the area around the unit free from clutter and flammable materials to reduce ignition risks.
Replace old or inefficient units that frequently fail ignition with models featuring modern electronic ignition and improved thermocouples.

What To Do If You’re Replacing The Pilot Assembly

When replacement is necessary, follow these guidance points to ensure a safe and correct installation.

Turn off the gas supply and electricity to the unit. Allow the heater to cool before handling components.
Consult the model-specific service manual or contact the manufacturer for compatible pilot assemblies and replacement parts.
Use proper gas-rated fittings and sealants. Avoid overtightening connections, which can cause leaks.
Test for leaks with soapy water after installation. Do not rely on odor or sight alone.
Consider professional installation for complex repairs or if the unit is older and shows multiple failure signs.

Choosing Between DIY And Professional Service

While many homeowners can safely light a standing-pilot or troubleshoot basic electronic-ignition issues, some scenarios require a licensed technician. Situations that warrant professional service include persistent ignition failures, gas odor, cracked components, water leaks near electrical connections, and units beyond basic maintenance.

Key Takeaways And Quick Reference

Know Your Model — Identify whether the heater uses a standing pilot or electronic ignition to follow the correct procedure.
Safety Always First — If you smell gas or suspect a leak, evacuate and call professionals immediately.
Patience And Technique — Allow adequate wait times for gas to dissipate and for thermocouples to heat when lighting a standing pilot.
Maintenance Reduces Risk — Regular inspections and cleaning improve ignition reliability and energy efficiency.
When In Doubt — Don’t hesitate to contact a licensed plumber or gas technician for complex issues or replacements.