Page 45
NOTE-
To obtain accurate reading, shut off all other gas
appliances connected to meter.
TABLE 18
GAS METER CLOCKING CHART
ML296
Unit
Seconds for One Revolution
Natural
LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-045
80
160
200
400
-070
55
110
136
272
-090
41
82
102
204
-110
33
66
82
164
Natural-1000 btu/cu ft LP-2500 btu/cu ft
IMPORTANT
For safety, shut unit off and remove manometer as
soon as an accurate reading has been obtained.
Take care to replace pressure tap plug.
G- Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas flow rate before checking com
-
bustion. See sections E- and F-. Take combustion sam
-
ple beyond the flue outlet. TABLE 19 shows acceptable
combustions.
The maximum carbon monoxide reading
should not exceed 100 ppm.
TABLE 19
ML296
Mode
l
CO
2
% For Nat
CO
2
% For L.P
Low Fire High Fire Low Fire High Fire
045
5.4 - 6.4
7.5 - 8.5
6.4 - 7.4
8.8 - 9.8
070
5.3 - 6.3
7.4 - 8.4
6.3 - 7.3
8.7 - 9.7
090
5.8 - 6.8
7.6 - 8.6
6.8 - 7.8
8.9 - 9.9
110
6.1 - 7.1
8.0 - 9.0
7.1 - 8.1 9.3 - 10.3
The maximum carbon monoxide reading should not exceed 100ppm.
H- High Altitude
The manifold pressure, gas orifice and pressure switch
may require adjustment or replacement to ensure prop
-
er operation at higher altitudes. See TABLE 20 for gas
conversion and pressure switch kits. See TABLE 21 for
manifold pressures
TABLE 20
LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes
Unit
Natural to
LP/Propane
High Altitude
Natural Burner
Orifice Kit
High Altitude LP/
Propane Burner
Orifice Kit
High Altitude Pressure Switch
0 - 7500 ft
7501 - 10,000 ft
7501 - 10,000 ft
4501 - 7500 ft
7501 - 10,000 ft
045
*11K51
73W37
*11K46
14A47
14A50
070
14A54
14A53
090
14A57
14A54
110
14A46
14A51
135
14A49
14A51
* Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit. Pressure switch is factory
set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1370 m).
TABLE 21
Manifold and Supply Line Pressure 0-10,000ft.
Unit
Gas
Manifold Pressure in. wg.
Supply Line
Pressure in. w.g
0 - 10,000 ft.
0 - 4500 ft
4501 - 5500 ft.
5501 - 6500 ft
6501 - 7500 ft
7501 - 10,000 ft
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Low
Fire
High
Fire
Min
Max
All
Sizes
Natural
1.7
3.5
1.6
3.3
1.5
3.2
1.5
3.1
1.7
3.5
4.5
13.0
LP/
Propane
4.5
10.0
4.2
9.4
4.0
9.1
3.9
8.9
4.5
10.0
11.0
13.0
NOTE - A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction
for the conversion procedure.