DuraVent Stove Pipe, HVAC, and Venting Equipment

A. A pellet stove pipe, also known as a vent pipe or chimney, is a specially designed pipe system that exhausts the smoke and harmful gases produced by a pellet stove or biofuel stove out of the house.

A. Listed pellet vent uses stainless steel for the inner wall, usually with a galvanized or painted steel outer wall. Stainless is not chosen for looks. Pellet exhaust is cooler and more acidic than wood smoke, so condensate forms readily inside the pipe and attacks lesser metals. Aluminum should not be used for pellet venting for the same reason, and neither should ordinary single wall black stove pipe, which is a different product for a different appliance. Buy pipe listed as pellet vent, sometimes marked type PL, and keep to one manufacturer's system so the joints and gaskets seal as designed.

A. A pellet appliance has an exhaust blower, so unlike a wood or oil stove it does not rely on natural draft to move its gases. The blower pushes exhaust through a sealed, gasketed pipe system to a termination outside. Because the system is sealed and fan-driven, it can run through a wall with a short horizontal section rather than needing a full vertical chimney, which is why pellet installations are usually simpler than wood ones. The run still needs the rise the manufacturer specifies, both to help the exhaust clear and to protect you if the power fails.

A. A short horizontal section through the wall is normal and is how most pellet stoves are vented, but the run should not be purely horizontal. Manufacturers specify a minimum vertical rise, and there are good reasons for it. Vertical rise gives the exhaust somewhere to go by natural buoyancy if the blower stops in a power cut, it reduces the chance of exhaust washing back against the building, and it keeps ash and condensate from sitting in a level pipe. Any horizontal portion should slope slightly upward toward the termination rather than running dead level. Follow the appliance manual for the exact rise and maximum run for your model.

A. The frequency of cleaning a pellet stove pipe depends on how often the stove is used. It is recommended to clean the pipe at least once a year to remove any creosote build-up and ensure proper ventilation.

A. No, a pellet stove pipe cannot be used for a wood stove. Wood stoves require a different type of pipe system designed specifically for them, namely single wall or double wall connector pipe in the room and insulated all-fuel chimney through the building. Wood produces far higher flue temperatures than a pellet appliance, and pellet vent is not built or listed for them.

A. Yes, a pellet stove pipe can be painted with high-temperature paint designed for use on stoves and other high-heat applications. However, it is important to follow the manufacturer's instructions for proper application and curing time.

A. Yes, and it is the usual arrangement. Because pellet vent is a sealed fan-driven system it does not need the full vertical chimney a wood stove requires, so a wall termination is both permitted and common. Use the listed wall thimble for the penetration, keep the manufacturer's minimum vertical rise, and site the termination clear of windows, doors, air intakes, walkways and anywhere snow drifts or sheds off a roof. Plan for a winter view of it too, since a termination you cannot reach in February is one you will not check after a storm.

A. The size of the pellet stove pipe depends on the size and output of the stove. It is important to consult the manufacturer's instructions or a professional installer to determine the correct size of the pipe for your stove.

A. Installation of a pellet stove pipe should be done by a professional installer or according to the manufacturer's instructions. The installation process involves cutting a hole in the roof or wall, assembling the pipe sections, and securing the pipe to the stove and the roof or wall.

A. Listed pellet vent runs cooler than wood connector pipe, so its required clearance is small, often a matter of inches, but the exact figure comes from the pipe listing rather than from a rule of thumb. Use the instructions supplied with the product. Two requirements apply at once: the vent listing governs the pipe and the appliance label governs the stove, including how much room it needs at the back and sides. Clearance is measured to combustible material, including framing hidden behind a finished wall. Do not assume that because pellet vent needs less clearance than wood pipe it needs none, and never pack insulation against it.

A. No, and this is the most important difference between a pellet appliance and the rest of what we sell. A pellet stove needs electricity for its auger, its controls and above all its exhaust blower, so it stops when the power does. That is why the vertical rise in the venting matters: it gives the exhaust in the pipe somewhere to go by natural buoyancy while the fire dies down, rather than drifting back into the room. If you rely on pellet heat in a place where outages are long, plan a battery backup or generator for the stove, or keep a non-electric appliance such as a gravity-fed oil stove or a wood stove as backup.

A. The distances come from the appliance and vent listings and from local code, and they are the rules most often broken in a retrofit. The purpose is to stop exhaust being drawn straight back into the building through an opening or a fresh air intake, and to keep the termination away from where people walk or where it can be blocked. Think about the whole year, not the day of installation. A termination that clears the ground in September can be buried in February, and one under an eave can be reached by snow sliding off the roof. Keep it away from a deck, a doorway and anywhere a drift forms, and check it after every heavy snowfall.

A. Often yes, and it is a common arrangement when a pellet stove replaces a wood appliance, but not by simply pointing the pipe into the old flue. A masonry chimney is far larger than a pellet appliance needs, so the exhaust cools, condensate forms and draft suffers. The correct approach is to run listed pellet vent, or an appropriately sized liner, all the way up inside the existing chimney and seal it at the top and bottom as the manufacturer specifies. The same principle applies to an existing all-fuel chimney. Confirm the appliance manual permits the arrangement, then size the liner to the appliance rather than to the opening.

A. Follow the appliance manual, because the answer depends on the stove and on the installation rather than on preference. Many pellet appliances accept 3 inch on short runs, and manufacturers commonly require 4 inch once the run gets longer, once several elbows are involved, or at higher elevations where thinner air reduces the exhaust flow. Going up a size on a long or elbow-heavy run is the usual recommendation, and going down a size is never a good idea, since restricting the exhaust upsets the combustion the stove is tuned for. Tell us the model, the total run and the number of elbows and we will confirm what the manual calls for.

A. On a sealed fan-driven system, smoke indoors means the seal or the flow has failed somewhere. The usual causes are a gasket or joint that has loosened, ash built up in the pipe or the appliance passages, a blocked or snow-covered termination, a failing exhaust blower, or a door or hopper seal that no longer closes tightly. Wind striking the termination can also push back against the exhaust. Shut the stove down and investigate rather than running it on, since incomplete combustion can produce carbon monoxide, and make sure the house has a working carbon monoxide alarm. Ash build-up is the most common cause by a distance, and it is the easiest to prevent with regular cleaning.