Class A Chimney, All Fuel Stove Pipe

A. An all-fuel stove pipe is a type of stove pipe that is designed to be used with multiple types of fuels, including wood, coal, gas, and oil.

A. All-fuel chimney is stainless steel where it matters. The inner liner is stainless because it meets the hottest, most acidic gases, and the outer casing is stainless or galvanized steel depending on the product and whether it is intended to be visible. Between the two walls sits packed insulation, which is what keeps the flue gases hot and the outer surface cool enough to run close to the building. Black painted steel is single wall connector pipe, a different product for use inside the room only, and it is never a substitute for all-fuel chimney.

A. While it is possible to install your own all-fuel stove pipe, it is recommended that you hire a professional to ensure that the installation is done correctly and safely. Improper installation can lead to chimney fires and other hazards.

A. Yes, all-fuel stove pipes can be used with masonry chimneys as long as they are installed correctly and meet local building codes and regulations.

A. Yes, all-fuel stove pipes can be used with fireplace inserts as long as they are installed correctly and meet local building codes and regulations. However, it is important to choose a stove pipe that is compatible with your specific insert model.

A. A pellet appliance must be vented with listed pellet vent, not with all-fuel chimney, because it is a sealed fan-driven system with cooler and more acidic exhaust. There is one arrangement that causes confusion. Where an existing all-fuel chimney is already in place, many pellet installations run pellet vent, or an appropriately sized liner, up inside it and seal top and bottom. That is using the existing chimney as a chase, which is not the same as venting the appliance with all-fuel pipe. Check the appliance manual, and size the liner to the stove rather than to the opening.

A. Yes, all-fuel stove pipes can be used with wood-burning stoves, as well as stoves that burn other types of fuels. Just make sure that the stove pipe you choose is compatible with the type of stove you have.

A. Yes, for the appliances all-fuel chimney is listed for, and oil-fired furnaces and boilers are the common case. That is what the name means: the product is listed for solid fuel and oil, so an oil furnace or boiler that needs a conventional flue is a normal application, whether the chimney is a listed all-fuel system or a properly lined masonry one. Two exceptions matter. High-efficiency condensing appliances vent through their own manufacturer-specified system, often plastic, because their exhaust is cool and wet. And a direct vent furnace uses its own sealed sidewall terminal instead. Always vent to the appliance manual.

A. To prevent creosote buildup in your all-fuel stove pipe, burn only dry, seasoned wood, and avoid burning trash, cardboard, or other materials that can produce excess soot and ash. Also, make sure to clean your stove pipe regularly to remove any creosote that may have accumulated.

A. To ensure that your all-fuel stove pipe is installed safely and correctly, hire a professional chimney service to do the installation. Make sure that the installer is licensed and insured and that they follow all local building codes and regulations. Also, be sure to have your stove and chimney inspected regularly to ensure that they are in good working condition.

A. Insulated all-fuel chimney is designed to run close to the building, and its listing states the required air space to combustibles. That clearance is small compared with connector pipe, but it is not zero and it must be maintained the whole way, including where the chimney passes through a ceiling, a floor or the roof. Two points catch people out. The air space must stay open, so never pack insulation, wood shavings or blown attic insulation against the chimney to close a gap. And penetrations must use the listed support box, firestop or flashing made for that system, which is what holds the required spacing where you cannot see it.

A. High enough to clear the roof and anything near it, which is what the widely used three-two-ten rule expresses: the chimney should extend at least three feet above the point where it passes through the roof, and at least two feet higher than anything within ten feet of it. This is not a formality. A chimney that finishes too low sits in the turbulent air that wind creates over a roof, and the draft becomes unstable, which shows up as smoke in the room when the wind shifts. Nearby trees, a taller adjoining roof or a snow load on the roof can all put the termination effectively lower than it looks on paper.

A. More than lengths of pipe, and this is where orders come up short. A typical installation needs the connector pipe in the room, a ceiling support box or wall thimble at the transition, the chimney lengths themselves, an attic insulation shield where it passes through an attic, roof flashing and a storm collar, bracing if the chimney extends well above the roof, and a cap. Elbows and offsets need their own supports. Order the whole system from one manufacturer so the listings and joints match, and count the components against the run before ordering, since a missing support box stops an installation on the day.

A. At the room boundary. Single wall or double wall connector pipe runs from the appliance up to the ceiling or across to the wall and stops there, in open air where it can be inspected and swept. All-fuel chimney takes over for everything that passes through the building and continues above the roof, joined at the transition with the listed support box or thimble. Connector pipe is never permitted inside a wall, ceiling or attic. If you are pricing an installation, budget for both parts from the start, because discovering at the ceiling that the chimney has not been ordered is a common and expensive surprise.

A. Yes, and for a gravity-fed oil drip stove the chimney is not an accessory, it is the engine. These appliances have no fan, so the natural draft created by the chimney is what pulls combustion air through the burner, and the chimney height and construction determine whether the stove burns cleanly at all. Too short and it will not draw enough air, giving a smoky sooty burn. Too tall and it can pull too much, cooling the burner and building carbon. Follow the appliance manual for the height range it is designed around, size the flue to the appliance outlet, and keep the run as straight as the building allows.

A. In three ways worth planning for. Ice can form on the cap and screen and choke the flue, which kills the draft and can push exhaust back into the house. Snow sliding off a metal roof can strike the chimney and bend or shift it, so site it clear of the shed path or fit snow retention above it. And deep snow on the roof effectively lowers the termination, which can spoil the draft in exactly the weather when the stove is working hardest. Check the cap after heavy snowfall and after any wind event, and if the chimney extends well above the roof, make sure it is braced for the load it will see.