Gas fireplaces don't require the extensive maintenance wood fireplaces do, because burning gas doesn't create the sooty residue that results from burning wood. Still, an annual cleaning helps ensure proper function of the gas fireplace by removing dust and dirt that could clog the burner. Follow the fireplace manufacturer's guidelines closely throughout the process. If you don't have the manual, ask a qualified professional to perform the cleaning during the fireplace's annual inspection.
Turn off the gas valve and the electrical power to the fireplace and allow it to cool.
Remove the logs and burner, following the specific directions provided by the manufacturer of the gas fireplace.
Bring the burner outside and scrub it gently with a toothbrush with soft bristles. Do the same for the logs.
Vacuum the interior of the fireplace thoroughly, including the burner assembly and the area around the pilot light.
Replace the burner and logs.
Turn the gas and electric power on so you can relight the pilot light, following the manufacturer's specific directions.
Hire a professional if you have any doubts about your ability to dismantle and reinstall the hardware. Gas fireplaces are safe to operate and easy to maintain, but you must know what you're doing.