4. Above a meter/regulator assembly within 3 ft (915
mm) horizontally of the vertical centerline of the
regulator.
5. Within 6 ft (1.8 m) of any gas service regulator
vent outlet.
6. Less than 1 ft (305 mm) above grade level.
7. Within 3 ft (915 mm) of a window or door which
can be opened in any building, any non-mechani-
cal air supply inlet to any building or the
combustion air inlet of any other appliance.
8. Underneath a verandah, porch or deck, unless the
verandah, porch or deck is fully open on a mini-
mum of two sides beneath the floor, and the
distance between the top of the vent termination
and the underside of the verandah, porch or deck
is greater than 1 ft (305 mm).
Venting Installation Tips
Support piping:
•
horizontal runs—at least every 5 ft (1.5m)
•
vertical runs—use braces
•
under or near elbows
29
Venting Configurations
For heaters connected to gas vents or chimneys, vent
installations shall be in accordance with the NFGC
(U.S.), or B149 (Canada), or applicable provisions of
local building codes.
Vertical Venting (Category IV)
Installation
The maximum and minimum venting length for this
Category IV appliance shall be determined per the
NFGC (U.S.) or B149 (Canada). See Table N and Fig.
23.
The minimum flue pipe diameter for conventional vent-
ing is: 4 in. (102mm) for Models 300A, 400A and 500A,
and 6 in. (152mm) for Models 700A and 850A.
The connection from the appliance vent to the stack
must be as direct as possible and shall be the same di-
ameter as the vent outlet. The horizontal breaching of
a vent must have an upward slope of not less than 1/4
Table N: Category IV Vertical Vent & Ducted Combustion Air
1
Vent lengths are based on a lateral length of 2 ft. Refer to the latest edition of the NFGC for further details.
* Subtract 10 ft per elbow. Max. 4 elbows.
** Only Centrotherm polypropylene is approved for the XFyre product.
Model
No.
Certified Vent Material
Vent &
Intake
Air Vent
Size
(in.)
Vertical Vent
Height
1
(ft)
Combustion
Air Intake
Pipe
Material
Vertical
Air Inlet
Max.
Length*
(ft)
WH
H
Min.
Max.
300A
(Canada Only:
ULC-S636 PVC
and CPVC)
Stainless Steel,
AL29-4C,
ANSI/ASTM
D1785 Sch 40
PVC,
ANSI/ASTM
F441 Sch 40
CPVC,
Polypropylene**
(Canada Only: ULC-
S636 PVC and CPVC)
Stainless Steel,
AL29-4C, ANSI/ASTM
D1785 Sch 40 PVC,
ANSI/ASTM F441 Sch
40 CPVC,
Polypropylene**
4
0
100
Galvanized
Steel,
PVC, ABS,
CPVC,
Stainless
Steel
100
400A
500A
700A
UL Listed Stainless
Steel, AL29-4C
ONLY
6
850A
CAUTION:
This venting system requires the
installation of a condensate drain in the vent piping
per the vent manufacturer’s instructions. Failure to
install a condensate drain in the venting system will
void all warranties on this boiler. Condensate is
acidic and highly corrosive
NOTE:
Ensure adequate clearances to allow annual
inspection of the venting system.
