Service manual

8
6-561.2
Rise X (in) Roof Pitch Min Height H (ft) 
0-6 Flat to 6/12 1.00
6-7 6/12 to 7/12 1.25
7-8 7/12 to 8/12 1.50
8-9 8/12 to 9/12 2.00
9-10 9/12 to 10/12 2.50
10-11 10/12 to 11/12 3.25
11-12 11/12 to 12/12 4.00
12-14 12/12 to 14/12 5.00
14-16 14/12 to 16/12 6.00
16-18 16/12 to 18/12 7.00
18-20 18/12 to 20/12 7.50
20-21 20/12 to 21/12 8.00
Section B - Vertical 2-Pipe Vent System
Installation
B1. This section applies to vertically vented 2-pipe (one
combustion air inlet pipe and one vent pipe) vent systems
and is in addition to “Section A - General Instructions - All
Units”.
B2. Vertical vent systems terminate vertically (up).
B3. It is recommended to install a tee with drip leg and clean
out cap as shown in Figure 8.1.
B4. The combustion air and vent pipes must be terminated with
(2) Gary Steel Model 1092 caps.
B5. Vertical vents must terminate a minimum horizontal and
vertical distance from roof lines and adjacent walls or
obstructions. These minimum distances are outlined in
Figure 8.1 and Table 8.1.
B6. The vent must terminate at least 1 foot above and 6 inches
horizontally from the combustion air inlet.
B7. Once venting is complete, proceed section titled “Installation
- Gas Connections”.
INSTALLATION - VENTING
Table 8.1 - Minimum Height from Roof to Lowest
Discharge Opening
 Size according to expected snow depth.
Figure 8.2 - Horizontal Venting with Downward Pitch
COMBUSTION AIR
EXHAUST
SLOPE 1/4" PER FOOT
DOWNWARD FROM UNIT
TEE WITH DRIP LEG AND
CLEANOUT CAP AT LOW
POINT OF VENT SYSTEM
SPECIFIED
TERMINAL
SUPPORT BRACKET
12" MIN
2' MIN
6" MIN
12"
ADJACENT
BUILDING
12" MIN
RECOMMENDED
4" MIN
TEE WITH DRIP LEG
AND CLEANOUT CAP
(SLOPE 1/4" PER
FOOT DOWNWARD
TOWARD DRIP LEG)
COMBUSTION AIR
EXHAUST
"H" MIN*
12" MIN
RECOMMENDED
4" MIN
BACK VIEW
ROOF PITCH IS:
X / 12
"H" MIN*
(SEE TABLE 8.1)
TEE WITH DRIP LEG
AND CLEANOUT CAP
(SLOPE 1/4" PER
FOOT DOWNWARD
TOWARD DRIP LEG)
ROOF FLASHING
USE LISTED THIMBLE
THROUGH ROOF AND
CEILING
COMBUSTION AIR
EXHAUST
12
X
LISTED TERMINAL
* SIZE ACCORNING
TO EXPECTED
SNOW DEPTH.
TO WALL OR ADJOINING BUILDING
12" MIN
12" MIN*
2' MIN
6" MIN
USE THIMBLE
THROUGH
CELLING
ROOF FLASHING
TERMINAL
TERMINAL
Figure 8.1 - Vertical 2-Pipe Vent System
Section C - Horizontal 2-Pipe Vent System
Installation
C1. This section applies to horizontally vented 2-pipe vent
systems (one combustion air inlet pipe and one vent pipe)
and is in addition to “Section A - General Instructions - All
Units”.
C2. Horizontal vent systems terminate horizontally (sideways).
C3. All horizontal vents must be terminated with a Gary Steel
1092 vent cap. The cap must terminate a minimum
distance from the external wall, as summarized in
Figure 8.2.
C4. The termination of horizontally vented system must extend
16 inches beyond the exterior surface of an exterior wall.
C5. The combustion air pipe must be a minimum of 12 inches
below the vent pipe, and 6 inches from the exterior wall.
C6. Construct the vent system as shown in Figure 8.2.
C7. When horizontal vents pass through a combustible wall (up
to 22 inches thick), the vent passage must be constructed
and insulated as shown in Figure 9.1.
C8. The vent must be supported as shown in Figure 9.1.
C9. When condensation may be a problem, the vent system
shall not terminate over public walkways or over an area
where condensate or vapor could create a nuisance or
hazard or could be detrimental to the operation of
regulators, relief openings, or other equipment.