How to Install a Gas Fireplace With a Direct Vent Into the Wall

Remove or peel back any existing siding surrounding the area where you will be installing the fireplace vent. Cut a hole between wall studs behind the location for the fireplace for the wall thimble. Check the package instructions for the exact dimensions of this opening. Frame the hole with short two-by-fours, using sections wide enough to reach from stud to stud on the horizontal. Frame only for the hole height specified for the vertical.

Screw the wall thimble to the inside of the framed box with the four enclosed screws. Attach a vinyl siding stand-off to the outside of the wall, covering the location of the wall thimble if your fireplace will be installed on a sided wall. Fit the termination cap over the protruding back of the wall thimble with the side marked "top" up. Level the termination cap and fasten it securely along the installation tab.

Measure the distance between the wall thimble and the back of the fireplace. Attach a coaxial pipe of the correct length to the back of the fireplace if the distance is greater than that of the short pipe that extends out the back of the fireplace unit. Install a flexible coaxial pipe if none of the precut pieces fits properly or the vent hole is not directly behind the fireplace.

Position your prepared fireplace unit in or on the fireplace surround. Use a team lift on the fireplace unit for a pedestal installation. Fit the fireplace outlet pipe into the wall thimble as you slide the unit into position. Center the fireplace unit so both installation fins have roughly the same amount of overlap on the framing if installing a custom surround. Level and plumb the fireplace unit with cedar shims. Secure the fireplace to custom surround framing with screws or to a prefabricated surround according to package directions.