Code Requirements to Pipe a Multi-Fuel Stove

Chimney

• When you add a multi-fuel or any solid fuel-burning stove to an existing masonry fireplace, you may need to make some changes to the chimney so it is compatible with the device. If the chimney is not approved for use with your appliance, you may need to reline it with a PL vent or single wall stainless steel pipe. Otherwise, the chimney opening may be too large to vent debris adequately, which will lead to creosote buildup. The safest solution is to connect a stainless steel liner directly from the stove to the top of the chimney. You should never connect the appliance to a flue being used by another appliance.

Stove Piping

• Use the type of stove piping required by the manufacturer of the stove. Most require a PL vent, which is double-walled and has a steel liner. The pipe must be 24-gauge or heavier metal. Some stoves allow a single wall stainless steel pipe, but only if you are venting up an existing chimney. The vent piping must meet the manufacturer guidelines and must fit the size of the stove's flue collar. Avoid more than two 90-degree elbows in the venting. Try to make the vents as short as possible and no longer than 8 to 10 feet.

Clearances

• Clearance guidelines are usually based on the type of piping you are installing, so review the manufacturer guidelines of the stove pipe. General fire safety codes should be followed for wall penetrations. If you're directing piping through a wall to a masonry chimney, there must be 18 inches of brick and mortar around the piping and you must install a fire clay thimble. If the piping is going through an exterior combustible wall, install a proper insulating wall thimble and a horizontal cap at the termination. For vertical piping, install ceiling support boxes, attic insulation shields, flashing and vertical caps. Review the chimney manufacturer's guidelines for clearances when it penetrates the roof. It may require 2 inches on all sides between the flue and combustibles.

Installation

• Review the manufacturer's recommendations for vent configurations before you attempt to install the stove. Direct venting through the wall may only be available on certain models. Other options include vertical venting and chimney relining. In any case, an approved chimney is required for most multi-fuel stoves. There may be recommendations for the maximum horizontal run and required slope of the run. Additionally, in air-tight homes, an installation of fresh air vent is often required for the stove's combustion.