DuraVent FasNSeal Severe Weather Wall Mount Insulated Kit: a wall vent kit for very wet, cold weather
The DuraVent FasNSeal Severe Weather Wall Mount Insulated Kit is a through wall vent kit for wall hung boilers and tankless water heaters. It helps keep the appliance from freezing while letting exhaust flow out. Inside are an insulated wall thimble, the sleeve through the wall, with a tee shaped outlet, an adjustable 90 degree elbow, and a universal appliance adapter with a condensate drain and back draft preventer. The latter blocks backward airflow. This 4 inch kit fits most appliances with a 4 inch exhaust. 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.
The outlet must be at least 12 inches above ground and the snow line, or higher if the appliance maker requires it. For deep snow, DuraVent suggests an additional outdoor 90 degree elbow and vent length to raise the outlet. In cold climates, drains must stay indoors. Need a kit for milder weather? See the DuraVent FasNSeal Standard Wall Mount Insulated Kit for ordinary weather. The DuraVent FasNSeal Severe Weather Wall Mount Insulated Kit ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
Details
SKU: FSSWWMKI04
Applications
FasNSeal is for use with natural gas or propane Categories II, III and IV appliances or Canada’s Type BH Gas Vent Systems, having a maximum rated operating temperature of 480°F and a maximum positive pressure of 15″ (FasNSeal Flex 6″) water column. FasNSeal can be used on a wide range of applications, including: high efficiency gas boilers, furnaces, booster heaters, pool heaters, water heaters, unit heaters, or tankless water heaters.
Materials and Construction
3″–7″: 29-4C or 316L stainless steel .016″
8″–12″: 29-4C or 316L stainless steel .019″
14″–16″: 29-4C or 316L stainless steel .024″
Diameters
3″ – 16″
Listings
UL Listed to UL 1738 and ULC S636.
FAQ
What makes this the Severe Weather wall-mount kit?
Its parts are chosen for extreme wet and cold: an insulated Wall Thimble with a Termination Tee, an adjustable 90-degree elbow and a Universal Appliance Adapter with a built-in condensate drain and a back-draft preventer. Together they keep the exhaust unobstructed and prevent the appliance freezing up. It is a 4-inch kit for wall-mounted boilers and tankless water heaters.
How is it different from the standard wall-mount kit?
The standard kit ends in a wall termination and a plain appliance adapter. This one terminates in a tee, adds the condensate drain at the adapter so freezing condensate cannot collect, and adds a back-draft preventer. DuraVent also suggests adding a 90-degree elbow and a vent length outside the house to lift the termination above high snow lines.
Which appliances can it vent?
Most 4-inch exhaust natural gas or propane appliances in Categories II, III and IV rated to 480 F and 15 inches water column, such as condensing boilers and tankless heaters, provided their manual lists a special gas vent like FasNSeal. The appliance manual also sets the maximum vent length and the termination distances from windows, doors and grade.
How do I connect and slope it?
Joints push together, turn until half the bead is covered, and the built-in locking band is tightened snug plus a quarter turn over the gasket; no sealant or screws. Pitch the horizontal run at least 1/4 inch per foot back toward the appliance, route the drain tubing with a trap loop and dispose of the acidic condensate per local code.
What clearance does the vent need through the wall?
The insulated thimble carries the pipe through the wall; elsewhere the clearance follows the FasNSeal manual’s Table 2 for the appliance’s rated temperature, for example 4 inches around an unenclosed horizontal run and 1 inch on a vertical run at a 300 F rating for single-wall 4-inch vent. Vent lengths and elbows for the outside rise are in the FasNSeal category.