How to Replace a Historic Wood Fireplace With a Gas Insert

Insert the Chimney Liner

• 1

  Climb the roof to access the chimney where it protrudes from the roof. Remove the existing chimney cap with a putty knife and drill, if necessary. If the chimney has a fireplace damper mechanism, remove this as well.

• 2

  Attach a heavy metal weight, such as a lead anchor or metal ring, to one end of a rope. Tie the other end of the rope to one end of the aluminum exhaust pipe from the gas flue liner kit. Have an assistant go into the house and kneel in front of the fireplace. Lower the weighted rope and then the aluminum pipe down the chimney flue and have your assistant catch both objects. He should then pull approximately 3 feet of pipe into the room then take the rope off the end of the pipe. Pull the rope and weight back up through the flue.

• 3

  Tie the rope to the end of the aluminum intake pipe. Drop the weight down the flue. Have your assistant catch and pull about 3 feet of pipe into the room then remove the rope from the pipe.

• 4

  Spread a thick bead of silicone caulk around the top of the chimney flue. Thread the two pipes though the hole in the aluminum boot then press the boot down onto the silicone and the top of the chimney flue. This boot covers the top of the flue and prevents water and debris from entering the chimney.

• 5

  Apply a thick bead of silicone caulk onto the pipe inlet holes on the termination fitting. Note that one inlet hole is larger than the other. Slip the end of the larger aluminum pipe into the larger inlet hole. Repeat for the other pipe and inlet hole. Drill two metal screws for each pipe to secure the pipes to the inlet hole flanges.

• 6

  Press the termination fitting onto the aluminum boot. Carefully snake the pipes deeper into the flue as you press the cap down. Screw the termination fitting onto the boot with metal screws.

• 7

  Screw the aluminum cap onto the termination fitting. Secure the cap onto the fitting. In the house in front of the fireplace, have your assistant pull the extra slack of pipes into the room and set them aside.

Install the Gas Insert

• 8

  Cut the extra length of aluminum piping until approximately 12 inches hangs down from the chimney flue into the fireplace cavity. The pipes are very flexible and will stretch if you need more slack.

• 9

  Stand the gas insert unit upright in front of the fireplace. With your assistant, slowly slide the unit toward the fireplace cavity. Leave the side of the unit with the gas connection exposed so you can attach the gas supply line.

• 10

  Connect the gas supply line's flexible tubing to the unit's gas inlet valve. Apply a small amount of pipe sealant to the gas inlet valve. Screw the flexible line onto the intake valve by hand then tighten the connection with a pair of adjustable wrenches.

• 11

  Push the remainder of the unit into the fireplace.

• 12

  Spread silicone caulk onto the small intake and exhaust sleeves on the top of the gas insert unit. Slip the larger aluminum tubing over the larger exhaust sleeve and the smaller aluminum tubing over the intake sleeve.

• 13

  Install the gas insert's decorative surround units. For most installations, the surround units clip into place or are secured with screws.