A pilot that lights and then goes out is different from a tank that simply needs more recovery time. The pilot flame is part of a fuel-burning safety system, so repeated relighting without understanding the failure can hide a gas-control, combustion, venting, or flame-sensing problem. Start with the heater label and manual, check for immediate gas or carbon-monoxide danger, and keep the homeowner task limited to the manufacturer’s normal lighting procedure and obvious external conditions.
START HERE
If you need the short version, try these steps first.
- Read the model and serial label and locate the exact lighting instructions on the heater or manufacturer documentation.
- Check the area for gas odor, a CO alarm, soot, damaged venting, flooding, or obvious physical damage before touching the control.
- Follow the specified OFF/wait/lighting sequence exactly once if the manual says homeowner relighting is appropriate.
Check these safety points before you start.
- If you smell gas, do not attempt to light the heater or operate electrical switches; leave the area and contact the gas utility or emergency service from a safe location.
- Never bypass, jumper, tape, or defeat a flame-sensing or gas-control safety device to keep a pilot burning.
- Suspected carbon monoxide, blocked venting, flooding, repeated ignition failure, or abnormal combustion requires qualified service rather than repeated homeowner relighting.
Gas odor or a CO alarm ends the troubleshooting session immediately
If you smell gas near the heater or in the building, do not try to light the pilot. Leave the area and follow your gas utility or emergency guidance from a safe location. Do not operate switches, plugs, flames, or other ignition sources while investigating a suspected gas leak.
A sounding carbon-monoxide alarm, visible soot, persistent yellow or unstable combustion, blocked or disconnected venting, or symptoms such as headache, dizziness, nausea, weakness, or confusion also move the situation out of ordinary pilot-light troubleshooting. Get to fresh air and follow emergency guidance for suspected CO exposure.
Use only the lighting procedure printed for your exact heater
A. O. Smith instructs owners to use the lighting directions on the water heater because ignition systems differ. Some units use a standing pilot and thermocouple or thermopile, while others use electronic ignition and status lights. The required OFF waiting period, control-knob position, igniter sequence, and hold time are model specific.
If there is no gas odor and the heater manual permits homeowner relighting, make one careful attempt exactly as directed. If the pilot will not light, lights but goes out again after the control is released, or the status light reports a fault, stop cycling the controls and move to diagnosis or service rather than improvising a longer hold time or external flame.
- Read the model and serial label and locate the exact lighting instructions on the heater or manufacturer documentation.
- Check the area for gas odor, a CO alarm, soot, damaged venting, flooding, or obvious physical damage before touching the control.
- Follow the specified OFF/wait/lighting sequence exactly once if the manual says homeowner relighting is appropriate.
- Observe whether the pilot flame appears and whether the status indicator shows a fault after the lighting attempt.
- If the pilot will not remain lit, return the control to the safe position described by the manufacturer and arrange service.
Flame-sensing and gas-control parts should not be defeated to keep the heater running
A pilot that repeatedly drops out can involve a thermocouple or thermopile that is not proving flame correctly, a gas-control problem, a weak or contaminated pilot flame, restricted fuel delivery, or other combustion-system faults. Modern systems may also lock out after abnormal ignition behavior.
Do not tape a control button down, jumper a thermocouple circuit, bend or bypass a safety switch, enlarge a pilot opening, or hold an external flame at the burner. Those actions defeat the system that is meant to stop gas flow when safe flame conditions are not proven.
Draft, venting, flooding, and nearby vapors can change the repair decision
A pilot that goes out during windy conditions, after construction, or after vent/chimney changes can indicate a draft or venting issue that needs qualified evaluation. Likewise, a heater that has been exposed to flooding or water around the gas controls should not simply be dried and relit without following manufacturer and gas-safety requirements.
Keep gasoline, solvents, and other flammable vapors away from gas water heaters. If the pilot problem follows a fuel interruption, utility work, a gas-control replacement, or repeated ignition failure, use a qualified gas-appliance technician rather than turning control or pressure adjustments yourself.
Before you call it done
- No relighting was attempted when gas odor, CO alarm, soot, damaged venting, flooding, or other immediate hazard was present.
- The exact heater model’s printed lighting procedure was used instead of a generic pilot-light sequence.
- Repeated relighting stopped after the pilot failed to stay lit or a status indicator reported a fault.
- Thermocouple, thermopile, gas-control, pilot-orifice, combustion, and venting work is being treated as qualified service rather than bypassed.
- Working CO alarms and safe clearance from gasoline or flammable vapors are part of the water-heater safety setup.