DuraVent FasNSeal W2 Fixed Blade Damper: a manual damper that holds boiler draft steady
The DuraVent FasNSeal W2 Fixed Blade Damper is a double wall manual fitting that controls a boiler’s draft, the pull on its exhaust. It sits as near the boiler outlet as possible. At startup, a professional sets the blade with a hand lever and tightens a locknut to hold that setting. It needs no electricity. FasNSeal W2 is DuraVent’s double wall stainless steel vent for high efficiency gas boilers, furnaces, and water heaters, with an air space between its two walls. That 1/2 inch air space helps shield nearby materials from heat.
Choose a 6, 8, 10, 12, 14, or 16 inch size on this page. The damper can sit in a vertical, horizontal, or sloped section, but it needs its own support rather than resting on the pipe. Adding this damper lowers the exhaust temperature rating for the entire vent run. The appliance maker sets the allowed route and length, so those limits matter before ordering. Need the single wall fitting? See the DuraVent FasNSeal Fixed Blade Damper. The DuraVent FasNSeal W2 Fixed Blade Damper ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.








Commercial projects may require custom parts and unique system designs. Duravent offers complete project assistance:








































