How do I Install a Vent in a Chimney Fireplace?

Installing a Chimney Vent

• 1

  Calculate the total British thermal units -- BTUs -- from all of the appliances that will share the chimney liner, and contact your municipal authority to find out what size chimney liner is required by local building codes. A liner that is too small will not allow the flue gases to reach the outdoors, while a liner that is too large can create many problems, including fire risk from creosote formation.

• 2

  Read the full instructions that come with the venting kit before beginning the project. Make sure that all safety precautions are taken before climbing on the roof, including checking the weather. Do not attempt the project if it is raining or there is excessive ice on the roof; and carefully remove any snow that may be present in the work area before beginning.

• 3

  Clean the chimney of any debris that may have collected over time. This can be messy and time consuming, depending on the age and condition of the chimney. Use the appropriate size and shape brush to scrub the interior walls or hire a professional to clean out the chimney. Use a drop light to inspect the condition of the chimney and note any areas that may need to be repaired prior to installing the liner.

• 4

  Reach inside the chimney and remove the chimney damper.

• 5

  Stretch out the new chimney liner and attach the insulation using approved tape according to the manufacturer's instructions.

• 6

  Attach a rope to the bottom connect and lower it down. Have someone at the bottom to assist. There may be a need to twist ever so gently to help move past bends or obstacles. The person on the bottom should guide the liner by pulling on the rope until it exits the chimney.

• 7

  Cut off any excess material once the liner is at its proper depth and attach the vent termination of the top according to the instructions. Make sure a high-quality silicone caulk is used to seal the termination.

• 8

  Attach the chimney liner to the fireplace. If more than a single appliance will share the liner, a Y connector may need to be installed. The vent would then run from the Y connector to both appliances. Make sure that the hole in the chimney is sealed with flashing or chimney concrete.