
508115-01
Issue 2043
Page 47 of 57
Gas Flow (Approximate)
Capacity
Seconds for One Revolution
Natural
LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-45
80
160
200
400
-70
55
110
136
272
-90
41
82
102
204
-110
33
66
82
164
Natural-1000 btu/cu ft LP-2500 btu/cu ft
Table 16. Gas Meter Clocking Chart
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas flow rate before checking
combustion. Take combustion sample beyond the flue
outlet and compare to Table 17.
Capacity
CO
2
% for Nat
CO
2
% for L.P.
All
7.2 - 7.9
8.6 - 9.3
The maximum carbon monoxide reading should not exceed
100 ppm.
Table 17.
High Altitude
NOTE:
In Canada, certification for installations at
elevations over 4500 feet (1372 m) is the jurisdiction of
local authorities.
Units may be installed at altitudes up to 10,000 ft. above
sea level. See Table 14 for de-rate manifold values. Units
installed at altitude of 7501 - 10,000 feet require an orifice
change. Units installed at altitudes of 4501 - 10,000 feet
(1373 to 3048 m) require a pressure switch change which
can be ordered separately. Table 15 lists conversion kit
and pressure switch requirements at varying altitudes.
The combustion air pressure switch is factory-set and
requires no adjustment.
Capacity
0-7,500 ft
(0-2,286m)
7,501 - 10,000 ft
(2,286 - 3,048 m)
Natural to LP/Propane
LP/Propane to Natural
High Altitude Natural
Burner Orifice Kit
High Altitude LP/Propane
Burner Orifice Kit
All
11K50+
73W80*
51W01
11K45+
* Conversion requires installation of a gas valve regulator spring which is provided with the gas conversion kit.
+ LP Kits include low line pressure switch.
Table 18. Burner Orifice Conversion Kits at Varying Altitudes
Capacity
0 - 4,500 ft.
(0 - 1,373 m)
4,501 - 7,500 ft.
(1,371 - 2,286 m)
7,501 - 10,000 ft
(2,286 - 3,048 m)
045
No Change
No Change
11J09
070
11J12
10U93
090
11U70
10U93
110
11J12
10U93
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4,500 feet (0-
1,370 m).
Table 19. Pressure Switch Requirements at Varying Altitudes