How to Install a Fireplace Gas Line

A gas fireplace lit in a dark room.
What You'll Need
Pipe cutter
Power drill and bit
Flexible gas line
Pipe wrench
Gas tight T-fitting
Plumbers tape or putty
Adjustable wrench
Spray bottle
Soapy water

Turn your wood fireplace into one that uses natural gas by adding a fireplace gas line that will fuel a new fixture or insert. This will require not only a good deal of work, but also material, time, and a some prior knowledge about installing a gas line. Keep in mind that this project can be dangerous if you don't know what you're doing. Any work involving natural gas will require special procedures to avoid gas leaks that can be fatal to you and your family. If you are confident that you can do this project and create a safe result, here are some of the steps you'll need to know and do.

Step 1 – Preparing to Install Your Gas Line

Before buying your materials, measure the distance you'll need to run the new gas line to the fireplace from either an existing line in the home or from a new source. Choose a route that will require few, if any, sharp bends that could kink the pipe and slow the flow of gas. Then, make a list of fittings and the lengths pipe you'll need, and take them with you to the hardware store. Check with your municipal building department for codes you will need to meet as well.

Step 2 – Shut Off Gas Service

Before making new gas line cuts or disconnecting gas pipe joints, shut off the gas between your connection point and the street gas pipe. Next, cut your existing line pipe where you plan to make your connection. Depending on the type of pipe your gas runs through in your house, use the type of pipe cutter that will work best.

Step 3 – Install Gas Line into the Fireplace

If your pipe is to run from your basement and through your floor to connect to the new fireplace, drill a hole in the floor nearby or up through floor of the fireplace itself, whichever will be closer to your gas pipe route. Run the other end of the gas line to the place where you cut the gas pipe. Then, attach a brass fitting to the fireplace gas valve, applying plumbers tape to the threads and tightening with a pipe wrench.

Step 4 – Connect Fireplace Line to the Gas Pipe

At the gas pipe where you made the cut, install a T-fitting that will connect both ends of the cut pipe and the fireplace pipe. Cut out a piece from the gas pipe long enough that both ends will fit on the T-fitting. Then, fit the end of the fireplace pipe on the unused end. Secure all three connections with plumbers tape or putty.

When finished, turn the gas back on and test all connections by spraying soapy water on them from a spray bottle. If you see bubbles at any of the connections, this means the connection with the bubbles is not tight. You'll need to tighten it further, or reconnect it with more plumbers tape or putty. It's also not a bad idea to get the line inspected professionally after your install, just to be sure everything is as safe as it should be.

With any loose connections and leaks taken care of, your old wood-burning fireplace is ready to receive a new gas replacement.