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NOTE- To obtain accurate reading, shut o all other gas 
appliances connected to meter.
TABLE 25 
GAS METER CLOCKING CHART
EL296
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 sample 
beyond the ue outlet. TABLE 26 shows acceptable com-
bustions. The maximum carbon monoxide reading should 
not exceed 100 ppm.
TABLE 26 
EL296
Model
CO
2
% For Nat CO
2
% For L.P
Low Fire High Fire Low Fire High Fire
045 5.6 - 6.6 7.8 - 8.8 6.6 - 7.6 9.1 - 10.1
070 5.5 - 6.5 7.3 - 8.3 6.5 - 7.5 8.6 - 9.6
090 5.9 - 6.9 7.8 - 8.8 6.9 - 7.9 9.1 - 10.1
110 6.3 - 7.3 8.2 - 9.2 7.3 - 8.3 9.5 - 10.5
The maximum carbon monoxide reading should not exceed 100ppm.
H- High Altitude
The  manifold  pressure,  gas  orice  and  pressure  switch 
may  require  adjustment  or  replacement  to  ensure  prop-
er  operation  at  higher  altitudes.  See  TABLE  27  for  gas 
conversion  and  pressure  switch  kits.  See  TABLE  28  for 
manifold pressures
TABLE 27 
LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes
Unit
Natural to
LP/Propane
High Altitude 
Natural Burner 
Orice Kit
High Altitude LP/
Propane Burner 
Orice 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 14A55 14A56
090 14A54 14A53
110 14A46 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 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.