A gas barbecue that does not light after the rain may have a wet igniter, clogged burners from water and grease getting into the ports, or the fuel supply may have simply run out during the last cookout. Gas grills are relatively simple appliances with minimal mechanical parts. Working systematically, you may be able to isolate and fix the problem and get back to grilling. No special tools are needed.
Unscrew the knob on the top of the gas tank if you use propane, or turn the handle on a natural gas line so it is parallel to the line.
Raise the grill lid and then push in and turn one of the burner control knobs to the ignite position. If you cannot hear or smell gas, check the tank and confirm that you have fuel, or contact the natural gas utility to determine if there is a service interruption. If you can detect gas, continue troubleshooting.
Press the grill's igniter button while looking at the appliance's underside. If you cannot see a spark jump from the igniter tip mounted below the grill, turn off the burner control and continue troubleshooting.
Wipe the igniter tip and along the wire to the back of the control panel with a clean, dry cloth. On some grills, the igniter system may include a battery pack mounted below the control panel, which contains a 9-volt battery. Open the compartment, remove the battery and wipe out any moisture. Dry and replace the battery.
Remove the cooking grate and the lava rocks or ceramic briquettes underneath and lift out the gate immediately above the burner.
Poking the tip of the nail or pin into each hole around the burner's circumference clears obstructions.
Blotting dry the burner with paper towels removes moisture.
Replace the grates and lava rocks or briquettes.
Ignite the grill normally. If the appliance still does not light, the rain may have shorted the igniter system. Replacement igniters for different grill models are available at hardware stores or from the manufacturer.