• In this video, This Old House plumbing and heating expert Richard Trethewey shows how to dramatically increase the heat output of a wood-burning fireplace.

    1. If necessary, use an angle grinder to cut and grind the bricks around the fireplace to create a flat, even surface.
    2. Have an electrician install a 110-volt electrical outlet to the rear corner of the fireplace.
    3. If there’s a gas line extending into the fireplace, shut off the gas, then use two pipe wrenches to unscrew the gas line.
    4. Brush pipe dope onto the threads of the gas pipe protruding into the fireplace, then cap off the line by installing a ½-inch cap.
    5. Remove the damper from the chimney, cutting it out with an acetylene torch, if necessary.
    6. If there are any bricks in the way, chop them out with a hammer and cold chisel or sledgehammer.
    7. Attach a pulling cone to the end of a stainless steel vent liner and tie a rope to the pulling cone.
    8. From the roof, drop the rope down the chimney. Feed the vent into the chimney while a helper down below pulls the rope to guide the vent into the fireplace opening.
    9. Make the electrical connections to the side of the fireplace insert.
    10. Remove the pulling cone from the vent liner, then attach an adaptor elbow to the end of the vent.
    11. Slide the fireplace insert partially into the fireplace opening. Reach into the fireplace and the plug the insert’s power cord into the electrical outlet.
    12. Pull down on the vent liner, then screw the adapter elbow to the top of the fireplace insert.
    13. From the roof, trim the vent liner to length with tin snips.
    14. Apply a continuous bead of high-temperature silicone sealant around the top edge of the flue tile protruding from the chimney.
    15. Install a chimney cap to the top of the chimney.
    16. Screw the surround panel to the face of the fireplace insert.

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    • Difficulty: Hard
      Requires precise installation and no fear of climbing onto the roof
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      Video Directory

      Selected Topic/Section

      Tools List

      • angle grinder
        Angle grinder, used to cut and grind fireplace bricks
      • pipe wrench
        Two pipe wrenches
      • acetylene torch
        Acetylene torch, used to cut out damper
      • hammer
        Hammer, sledgehammer and cold chisel, for chopping out fire bricks
      • pulling cone
        Pulling cone and rope, used to pull the vent down the chimney
      • multi-bit screwdriver
      • nut driver
        Nut driver
      • metal cutting snips
        Tin snips
      • caulk gun
        Caulk gun

      Shopping List

      Wood-burning fireplace insert

      Pipe dope

      ½-inch cap

      6-inch-diameter stainless steel vent liner

      High-temperature silicone sealant

      Chimney cap