13
•
Always use a back-up wrench when making the
connection to the gas valve to keep it from turning.
The orientation of the gas valve on the manifold must
be maintained as shipped from the factory. Maximum
torque for the gas valve connection is 375 in-lbs;
excessive over-tightening may damage the gas valve.
•
Install a manual shutoff valve between the gas meter
and unit within six feet of the unit. If a union is installed,
the union must be downstream of the manual shutoff
valve, between the shutoff valve and the furnace.
•
Tighten all joints securely.
Natural Gas Capacity of Pipe
In Cubic Feet of Gas Per Hour (CFH)
Length of
Nominal Black Pipe Size
Pipe in Feet
1/2"
3/4"
1"
1 1/4"
1 1/2"
10
132
278
520
1050
1600
20
92
190
350
730
1100
30
73
152
285
590
980
40
63
130
245
500
760
50
56
115
215
440
670
60
50
105
195
400
610
70
46
96
180
370
560
80
43
90
170
350
530
90
40
84
160
320
490
100
38
79
150
305
460
(Pressure 0.5 psig or less and pressure drop of 0.3" W.C.; Based on
0.60 Specific Gravity Gas)
CFH = BTUH Furnace Input
Heating Value of Gas (BTU/Cubic Foot)
•
Connection method must be in compliance with all
local and national codes. US: National Fuel Gas
Code (NFGC) NFPA 54-2012/ANSI Z223.1-2012 and
the Installation Standards, Warm Air Heating and Air
Conditioning Systems ANSI/NFPA 90B.
In Canada, CANADA: National Standard of Canada,
Natural Gas and Propane Installation Code
(NSCNGPIC) CSA B149.1-15.
Connect the furnace to the building piping by one of
the following methods:
─ Rigid metallic pipe and fittings.
─ Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in
exterior locations. In order to seal the grommet
cabinet penetration, rigid pipe must be used to
reach the outside of the cabinet. A semi-rigid
connector to the gas piping may be used from
there.
•
Use listed gas appliance connectors in accordance
with their instructions. Connectors must be fully in the
same room as the furnace.
•
Protect connectors and semi-rigid tubing against
physical and thermal damage when installed. Ensure
aluminum-alloy tubing and connectors are coated to
protect against external corrosion when in contact
with masonry, plaster, or insulation, or subjected to
repeated wetting by liquids such as water (except rain
water), detergents, or sewage.
The gas piping may enter the left or right side of the furnace
cabinet. The installer must supply rigid pipe long enough to
reach the outside of the cabinet to seal the grommet cabinet
penetration. A semi-rigid connector to the gas piping can
be used outside the cabinet per local codes. 1/2” NPT pipe
and fittings are required. For models with an “L” shaped
manifold, a 4 1/2” long nipple is required. For models with a
hook shaped manifold, a 2” long nipple is required.
A semi-rigid connector to the gas piping can be used
outside the cabinet per local codes. From the elbow, the
length of pipe and the fittings required will vary by the side
chosen, location of union and cabinet width. The union may
be placed inside or outside of the cabinet.
Alternate
Gas Line
Location
Gas Valve
Burners
Manual Shut Off Valve
(upstream from
ground joint
pipe union)
Drip Leg
Grommet
in Standard
Gas Line
Hole
*Ground
Joint
Pipe
Union
*Ground
Joint
Pipe
Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
Manifold
Upflow
Figure 6
Alternate
Gas Line
Location
Plug in
Alternate
Gas Line
Hole
Gas Valve
Burners
Manual Shut Off Valve
(upstream from ground joint pipe union)
Drip Leg
Grommet
in Standard
Gas Line
Hole
*Ground
Joint
Pipe Union
*Ground
Joint
Pipe Union
*NOTE: Union may be inside furnace cabinet where allowed by local codes.
Counterflow
Figure 7
SYSTEM OPERATION
