WHAT IS SPECIAL GAS VENT? A system designed to exhaust natural gas or propane burning, category II appliances, category III appliances, or category IV appliances, or Type BH systems. This venting system is designed to handle high efficient appliances. This type of system is listed to UL 1738, ULC S636, or UL 1777.


Single-Wall and Double-Wall Special Gas Vent Boiler Applications.

FasNSeal® 80/90

Combined Category I and IV venting for Gas-Burning Appliances.


Special gas vent system. UL 1738 and ULC S636.

FasNSeal® Flex

Flexible special gas vent system. The only flex Listed to UL 1738. UL 1777.

FasNSeal® W2

Double-wall special gas vent system. UL 1738 and ULC S636.