This occurs more often than you think. Upon inspection of a fireplace, we find the gas valve for the fireplace is located INSIDE the firebox. The fact of the matter is, if the valve is located inside the firebox, then the valve has to be removed, capped off and relocated.
According to the California International Residential Code and National Fire Protection Association 54 (also referred to as the National Fuel Gas Code), the “appliance shutoff valves…shall serve a single appliance and shall be installed within six feet of the appliance it serves, and shall be readily accessible and permanently identified.”
In addition, “…appliance shutoff valves installed in fireplaces shall be removed and the piping capped gastight…..”
If you think about it, having a gas valve inside a firebox is not a good idea. Who wants to turn off a valve by having to stick your hand inside the firebox while a fire is going?
Another key point to this issue is “readily accessible.” The gas valve must be where it can be easily seen and within view. It should not be located in a crawl space, inside a cabinet or around the corner in a hall.
If you have a gas valve located inside your firebox, contact a licensed plumber who specializes in gas to cap off the gas pipe and relocate the gas valve.