How to Turn on a Gas Fireplace With a Wall Key

For the perfect combination of comfort, low maintenance, and ease of operation, gas fireplaces can’t be beat. Gas is clean, and it burns warm. Plus, you never need to clean up ashes later on. 

While some gas fireplaces ignite with the flip of a wall switch, other fireplaces are lit by turning a wall key while applying flame from a lighter or long match. Operation is fast, easy, and safe—as long as you follow the lighting procedure in the correct manner.

Where to Find the Gas Valve Knob

The gas valve knob is the junction between the main gas pipe and the gas fireplace. When closed, the gas valve knob acts as a gate to prevent gas from flowing to the fireplace. When opened, gas will flow. The valve can be opened partially or in full.

The gas valve knob usually has a round metal flange with a square or hex hole in the center. It will be located:

• On the wall on either side of the fireplace, usually about a foot off the floor; or
• Ground-level on the fireplace apron; or
• Ground-level on the flooring around the fireplace

Safety Considerations

Flammable and potentially dangerous, natural gas is colorless and odorless. To help with detection, gas companies treat natural gas with trace amounts of mercaptan, a pungent odor similar to rotten eggs or sulfur. 

If you smell significant natural gas build-up in the home, turn off the gas to the fireplace, open all windows and exterior doors, and leave the house until the smell is gone.

When turning, do not force the key. This may break the gas valve knob or the key.

Troubleshooting Turning on a Gas Fireplace With a Wall Key

Cannot Find the Pilot Light

Wall key gas fireplaces do not have pilot lights. Manually lighting the fireplace substitutes for the pilot light. Gas fireplaces that operate with wall switches do have standing pilot lights, though.

Gas Flows but Won’t Light

Turning the wall key alone will not light the gas fireplace. You do need to apply a flame to flowing gas to light the fireplace. If the gas is flowing, the problem may be with the flame. Turn up the flame on the kitchen lighter or use a new lighter.

Wall Key Is Lost

It can be easy to misplace the fireplace wall key since it should never be left in the gas valve knob. Look on the fireplace mantel, on the fireplace apron, or in a nearby shelf or cabinet. It’s also helpful to look in the kitchen if you have a drawer with general items. If you still can’t find the key, buy a new one for $5 to $7 at your local home center or hardware store.