Water heater gas pilot keeps going out will light then extinguish: What to Check and What to Do Next

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   Before trying to relight anything, stand clear of the burner opening and check only from ordinary safe access for a gas odor, hissing, smoke, soot or discoloration, flame outside the intended viewing area, an unusual combustion odor, or a carbon-monoxide alarm. Do not use a match, lighter, switch, or tool to investigate.

   Expected result: There is no gas odor, smoke, soot, flame rollout, unusual combustion odor, alarm, or other immediate hazard, or one of those warning signs is present.

   Next step: If a warning sign is present, do not relight or operate the heater; leave the area when appropriate and contact the gas utility or emergency service from a safe location. If none is present, continue only with the exact lighting instructions for the installed model.

   Stop if: Stop immediately for gas odor, hissing, smoke, soot, flame rollout, an alarm, or an appliance part that appears damaged or has been under water.

   Why this matters

   Why: A clean visual and odor screen permits only the model-specific relight check. Any gas or combustion warning makes relighting unsafe and can indicate a leak, venting, or combustion problem rather than a simple pilot adjustment.

2. Check 2

   With no hazard signs present, read the lighting label and the exact model manual, set the control only as instructed, and use the built-in igniter or other specified method. Keep the burner door and any sealed combustion barrier in the configuration required by the manual; do not use tools or hold a control against its stop.

   Expected result: The pilot produces the expected flame and remains lit after the manual's release step, or it goes out immediately at release, will not light, or requires repeated attempts.

   Next step: If the pilot remains lit, observe it during a normal heating call without opening the compartment. If it dies or needs repeated attempts, turn the control to the manual's safe position and arrange qualified service; do not keep relighting it.

   Stop if: Do not open an inner burner door, hand-light a sealed assembly, bypass a thermocouple or thermopile, force a knob, or continue if the knob does not operate as instructed.

   Why this matters

   Why: A pilot that dies at release makes the flame-sensing path, pilot flame, connection, or gas control more likely. A pilot that will not light points instead toward the igniter, gas supply, pilot tube or orifice, or control position. Repeated failure is not a successful repair.

3. Check 3

   Without removing doors or panels, observe the pilot through the heater's intended viewport or viewing opening while following the model instructions. Note whether the flame is steady and reaches the flame-sensing tip, is very small or yellow, flickers in a draft, or cannot be seen clearly.

   Expected result: The flame is stable and appropriately directed, or it is weak, yellow, lifting, repeatedly disturbed, or not contacting the sensor as the design requires.

   Next step: Record the flame behavior and the exact model for the technician. Do not poke the pilot, insert wire, clean an orifice, reposition a sensor, or alter the gas-air mixture from the viewing area.

   Stop if: Stop use for a yellow or lazy flame, flame lifting or rolling out, soot, combustion odor, or any need to remove the burner door or touch the pilot assembly.

   Why this matters

   Why: A stable flame that still drops out shifts suspicion toward the thermocouple or thermopile connection, safety circuit, or gas control. A weak or abnormal flame can reflect a restricted pilot path, low gas pressure, cold draft, inadequate combustion air, or venting trouble; those causes require service-level diagnosis.

4. Check 4

   From a safe position, inspect the accessible air-intake openings, the area around the heater, and the visible vent termination for dust, stored items, nests, snow, leaves, or other obvious blockage. Move only loose household items that can be removed without opening the heater, climbing, disassembling venting, or touching gas components.

   Expected result: The intake and visible termination are clear, or an obstruction, strong draft, damaged vent, or inaccessible section is found; note whether the pilot fails immediately or only after the burner has run.

   Next step: If an obvious loose obstruction outside the heater can be removed without contact with the appliance, remove only that item and leave the heater off until the manual allows a single restart. If the vent is damaged, blocked, inaccessible, or the pilot still fails, arrange qualified service.

   Stop if: Do not remove vent sections, open the combustion chamber, clean a flue internally, climb to an unsafe termination, or operate the heater with a damaged or obstructed vent.

   Why this matters

   Why: Clear openings do not prove that combustion air and venting are correct, but an obstruction or a failure that occurs during a heating cycle makes air, draft, or venting concerns more plausible. The service manual also lists inadequate combustion air and incorrect or clogged vent systems for periodic pilot outages.

5. Check 5

   Without changing gas settings, note whether other gas appliances work normally and record the water-heater control type, fuel type, status-light pattern if present, exact model and serial information, and when the pilot goes out: immediately at release, during a burner call, or after a longer interval.

   Expected result: Only this heater has the symptom, several gas appliances also lose fuel, the control reports a diagnostic pattern, or the timing is repeatable during heating cycles.

   Next step: Give the observations, photos from safe access, model information, and the exact relight result to the gas utility or qualified water-heater technician. Do not measure pressure or electrical output yourself.

   Stop if: Stop all testing for gas odor, abnormal flame, soot, combustion odor, an alarm, or any request to bypass a safety control or open the gas train.

   Why this matters

   Why: A broader loss of gas service makes a utility-side supply issue more plausible; a single heater with an immediate dropout points toward its pilot-sensing or gas-control path; a periodic dropout during heating keeps combustion air, venting, and supply stability in the decision. A status-light code is model-specific and should not be guessed.