Lennox EL297UH070XV36B - Proper Combustion and High Altitude

Page 81
NOTE- To obtain accurate reading, shut o all other gas
appliances connected to meter.
TABLE 26
GAS METER CLOCKING CHART
EL297
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
-135 27 54 68 136
Natural-1000 btu/cu ft LP-2500 btu/cu ft
IMPORTANT
For safety, shut unit o󰀨 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 ow rate before checking com-
bustion. See sections E- and F-. Take combustion sam-
ple beyond the ue outlet. TABLE 27 shows acceptable
combustions. The maximum carbon monoxide reading
should not exceed 100 ppm.
TABLE 27
EL297
Model
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
135 6.1 - 7.1 7.8 - 8.8 7.1 - 8.2 9.1 - 10.1
The maximum carbon monoxide reading should not exceed 100ppm.
H- High Altitude
The manifold pressure, gas orice and pressure switch
may require adjustment or replacement to ensure proper
operation at higher altitudes. See TABLE 28 for manifold
pressures. See TABLE 29 for gas conversion and pres-
sure switch kits.
TABLE 28
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
Natuarl 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.
TABLE 29
LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes
Unit
Natural to
LP/Propane
High Altitude
Natural Burner
Orice Kit
High Altitude LP/
Propane Burner
Orice 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
14A51 14A53
070 14A48 14A54
090 14A54 14A53
110 25B93 14A45
135 25B94 25B95
* 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).