UTICA BOILERS UCS 380 Installation, Operation And Maintenance Manual page 28

FIGURE 6-7 Two Pipe Roof Vent
12" (305mm) Min.
12" (205mm) Min.
or greater separation
84" (2134mm) Max.
is manufacturer
recommended
Vent
12" (305mm) US,
18" (458mm) Canada
Minimum Above
Anticipated Snow Line
FIGURE 6-8 Two Pipe Side Wall Vent
3" (76mm) Min.
24" (610mm) Max.
Separation
Opening
Separation
24" Min.
See Grade
Snow & Ice
FIGURE 6-9 Two Pipe Side Wall Vent (Multiple
Appliances).
See Grade
Snow & Ice
Combustion Air
6 - COMBUSTION AIR AND VENT PIPING
12" (205mm) Min.
15"
(381mm)
Max.
Combustion
Air
12"(305mm)Min.
From Overhang
12" (305mm) Min.
24" (610mm) Max.
Separation Between
Bottom Of
Combustion Air Intake
And Bottom Of Vent
Vent
Combustion Air
12" (305mm) Min.
Separation
Manuf. Recommends
Greater Separation
Vent
Roof Line
Roof
Terminations
Side Wall
Terminations
Grade, Snow &
Ice
Doors &
Windows
26
 12" (205mm) Min. horizontal separation
between combustion air intake and vent
of same appliance.
 12" (205mm) Min. 84" (2134mm) Max.
vertical separation between combustion
air intake and vent of different
appliances.
 15" (381mm) Max. horizontal length of
vent.
 Min. vent/intake between different
appliances 12" (305mm).
 Max. allowable total vertical vent length
with outside exposure is 10 ft.(3.05m).
 Abandoned unused masonry
chimney may be used as chaseway
for combustion air and vent. Both
combustion air and vent pipe must exit
above top of chimney with clearances as
shown in figure 6-7.
3" (76mm) Min. 24" (610mm) Max.

Separation horizontal separation
between combustion air intake and vent
terminations.
 12" (305mm) Min. vertical separation
between combustion air intake and vent
terminations.
 12" (305mm) 24" (610mm)
min.
Max. separation between bottom of
combustion air intake and bottom of
vent.
 Multiple terminations as shown in 6-7,
and 6-10 must be a min. of 12" (305
mm) horizontally between vent of
one termination and air intake of next
appliance. Manufacturer recommends
greater separation.
 Max. allowable total outside exposure
vent length equals 10 ft. (3.05m).
 Maintain a pitch of 1/2" per ft.
(42mm/m) outside exposure back to
boiler to ensure proper condensate
drainage for horizontal runs.
Maintain 12"(305mm) US (18"(457mm)
Canada) clearance above highest
anticipated snow level 24" (610mm) above
roof or ground.
Avoid locations where snow may drift and
block vent and combustion air. Ice or snow
may cause boiler to shut down if vent or
combustion air becomes obstructed.
Combustion air and vent termination must
be 12" (305mm) from or below doors,
windows or gravity inlet.
PN 240011662 Rev. K [01/31/2020]