DuraVent FasNSeal Fixed Blade Damper: set once to keep boiler draft in check
The DuraVent FasNSeal Fixed Blade Damper is a manual vent damper that sits close to the boiler’s exhaust outlet. A professional sets its blade during boiler startup to keep draft, the pull through the boiler, from exceeding the boiler maker’s limit. A hand lever positions the blade, and a locknut holds that setting. It needs no power. FasNSeal is DuraVent’s stainless steel vent for high efficiency gas boilers, furnaces, and water heaters, built to carry pressurized exhaust and its acidic condensate outside. It serves natural gas or propane appliances whose makers specify a special gas vent.
Choose a 6, 8, 10, 12, 14, or 16 inch size on this page. The damper needs its own support rather than resting on the pipe. Adding it lowers the exhaust temperature rating of the whole vent, so the installer checks compatibility with the boiler. Single wall pipe also needs an open air gap from anything that can burn, with the spacing determined by exhaust temperature. Need the double wall version? See the DuraVent FasNSeal W2 Fixed Blade Damper. The DuraVent FasNSeal 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:








































