[header] How to clean a gas fireplace [title] Turn the gas off. [step] Before you begin cleaning your gas fireplace, you must first make sure you turn the gas valve to the " off " position. If you leave the gas running, it could cause a dangerous gas leak in your house. 
[substeps] The gas valve is typically on the wall next to the fireplace. Allow a few minutes for all the gas to leave the piping in the fireplace.