How to Replace Gas Fireplace Inserts

A framed fireplace with a gas insert.
  • 10-20 hours
  • Advanced
  • 500-5,000
What You'll Need
Sandwich bag
New insert
Self-tapping screws

Replacing your gas fireplace insert can be an easy home project; if you have the right tools, this job can be done in a short time. However, since this project involves working around gas lines, you will need to make sure you take a safe approach. Here are a few helpful steps you can follow.

Step 1 - Turn off the Utilities

The first thing you must do is turn off the gas to the house and the breaker that supplies electricity to the fireplace itself. This is very important because you will be unhooking the gas line from the old insert. This will prevent gas from leaking into your home and creating a health and fire hazard.

Step 2 - Remove the Fireplace Doors

Begin by unscrewing the fireplace doors and taking them off. So you don’t lose any screws, be sure to set them aside in a plastic sandwich bag while you work.

There is a grate on the inside of the fireplace that also needs to be removed, but first, you'll need to clean out all the ashes. This will help to prevent any unwanted mess while you change the fireplace insert.

Step 3 - Remove Insert

Slowly remove the fireplace insert. It should still be connected to the gas line at this point, so you don’t want to pull too hard and damage it.

Step 4 - Disconnect the Hookups

Man installing a fireplace insert

Once you have the insert where you can see the connections, you can unhook them. They may be threaded together so you may need to use a wrench. With the gas and electric lines removed, you should be able to slide the insert out the rest of the way without a problem.

Step 5 - Install the new Insert

Since this is not a fresh install, the vent pipes should already be in place and properly insulated, so all you'll need to do is just slide in and connect the new insert.

Make sure your replacement gas fireplace will fit before you purchase it. Measure the opening or the dimensions of your current model and buy a new one accordingly.

After you have the new fireplace on hand, check to see it is level. Adjust it as needed by adding some small pieces of wood underneath the legs.

Now, you can slide the new insert into place. Stop before it's all the way in and reconnect the gas line and electric lines. Once the insert is in, be sure the connecting plates are in the slots, and secured with self-tapping screws.

Step 6 - Add the Fire Logs and Grate

flame in a fireplace insert

Carefully open up the insert by removing the screws on each side of the doors or cover. Load the embers, logs, and grate. The embers need to be scattered over the burning plates before you add the logs. When you're done, place the glass doors or cover back into place. Then, program the remote control after you install the receiver.

Step 7 - Check for Gas Leaks

Check for leaks after switching the gas and electricity back on. If you smell any gas, call for a professional to come in and fix it; if there are no leaks, be sure the heat is headed up the flue and the exhaust is going out of the chimney like it's supposed to. Then you should be all set to sit by a warm, cozy fire with your new fireplace insert.