A gas fireplace is not designed to burn wood; burning wood in it could be a fire hazard, or, at the very least, fill your home with smoke. Some gas fireplaces have all the necessary safety features to burn wood if you wish to convert the fireplace entirely to a wood-burning version. Modification and complete safety checks are required before burning wood in the gas fireplace.
Gas-Only Fireplace Concerns
A fireplace installed as a gas-only unit is not designed to burn wood; it does not have the same type of ventilation, flue and firebox, and it isn't designed to handle the creosote, smoke, ashes and soot that result from burning wood. Burning real wood in the gas fireplace could be a fire hazard or safety issue, beyond just filling your home with smoke.
Converting to Wood
Some gas fireplaces are built with the same type of masonry and ventilation system required for a wood-burning fireplace. Many gas fireplaces in older homes were once designed to burn wood, but later converted by adding a gas line. In either case, a fireplace installer can determine whether your fireplace can be converted to a wood-burning version. If it can be converted, the gas line is capped. If not, the entire fireplace would have to be replaced to burn wood -- if your chimney can handle it.
Even if your fireplace can handle conversion to wood, the chimney and flue must be inspected to ensure they are in good condition; otherwise, harmful fumes and smoke may enter your home when you're burning wood. A chimney inspector can determine whether the masonry, tiles and the damper are in good shape. The damper allows you to adjust the ventilation required for burning wood; if it doesn't function properly, you cannot safely burn wood. You may also need to have the chimney cleaned before converting to the fireplace to burn wood; the inspector will inform you of all such concerns. If all of the chimney and fireplace parts are in great shape, the fireplace is ready to convert to a wood-burning version of itself. Ask a local chimney installer if they can cap the gas line and safely convert it for you.