DuraVent FasNSeal

Where this vent belongs

This special gas vent carries pressurized exhaust and acidic condensate from high efficiency gas appliances and belongs to our DuraVent Commercial range. A vent system is tested as one maker's system, so use approved components from this line throughout the run, with professional installation and a qualified inspection each year. DuraVent PolyPro is plastic vent for condensing appliances whose manuals allow it. DuraVent B vent serves older natural draft appliances with a draft hood. Our B Vent Pipe collection groups that vent type, and these gas vent systems are not interchangeable with this line.

Single wall or FasNSeal W2?

Both versions are built for positive pressure, but the single wall pipe needs an open air gap from combustible materials. FasNSeal W2 adds a stainless outer wall and half inch air space, allowing clearance as close as 1 inch depending on exhaust temperature and enclosure. It fits inside walls and between joists and allows outdoor runs below the roof without an enclosure. W2 stays uncut, and adapters change a run from one version to the other, each in one direction only.

What your run needs

Straight lengths have a gasket and locking band, with 2 inches of overlap at each joint. The gasket and locking band on every length are there for ease of installation. An adjustable length helps fit the remaining distance without trimming pipe. Start with an appliance adapter, then account for condensate drains, test ports and any elbows, tees, increasers or reducers. Wyes join branches for common venting only when the appliance maker approves it. Complete the route with support components, a wall thimble or roof flashing, and an approved termination, or check whether a wall mount or unit heater kit suits your appliance and route.

A flex liner for an existing chimney

FasNSeal Flex carries gas exhaust up an existing masonry chimney, straight or nearly straight, never sideways. It uses rigid parts beyond the chimney at both ends. Compare it within our chimney liner collection and follow your appliance manual.

Why buy from My Cozy Outdoors?

We are an authorized DuraVent dealer, and the full manufacturer warranty applies. Our DuraVent brand page groups the maker's lines by what they vent. Send us the appliance model and a sketch of the run and we will write the parts list.

Common questions

What is FasNSeal vent used for?

It vents high efficiency gas boilers, furnaces, water heaters and unit heaters whose manuals call for this vent type. The stainless pipe, sealed joints and drains handle pressurized exhaust and acidic condensate. It serves natural gas or propane appliances, never wood or pellets.

What is the difference between FasNSeal and FasNSeal W2?

The single wall pipe needs an open air gap from combustible materials. W2 adds a second stainless wall with a half inch air space. Its clearance can be as little as 1 inch, depending on exhaust temperature and enclosure, and the double wall pipe must stay uncut.

Can FasNSeal pipe be cut to length?

W2 pipe cannot be cut, and only a professional may trim the single wall pipe at its narrower end. DuraVent prefers adjustable lengths. Send us the appliance model and a sketch of the run and we will write the FasNSeal parts list.