Lennox International Inc Elite Series Gas Furnace Proper Combustion, High Altitude Information

Proper Combustion

High Altitude Information

Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking com­ bustion. Take combustion sample beyond the flue outlet and compare to the tables below.

TABLE 16

EL296	CO2% For Nat	CO2% For L.P
Model	Low Fire High Fire	Low Fire High Fire

0455.4 - 6.4 7.5 - 8.5 6.4 - 7.4 8.8 - 9.8

0705.3 - 6.3 7.4 - 8.4 6.3 - 7.3 8.7 - 9.7

0905.8 - 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 50 ppm.

NOTE - In Canada, certification for installations at eleva­ tions over 4500 feet (1372 m) is the jurisdiction of local au­ thorities.

Units may be installed at altitudes up to 10,000 ft. above sea level without manifold adjustment. Units installed at al­ titude of 4501 - 10,000 feet (1373 to 3048m) may require a pressure switch change which can be ordered separately. Table 18 lists conversion kit and pressure switch require­ ments at varying altitudes.

The combustion air pressure switch is factory-set and re­ quires no adjustment.

TABLE 17

Manifold and Supply Line Pressure 0-10,000ft.

EL296		Manifold Pressure in.wg.		Supply Line Pressure in. w.g.
	Gas
Unit
		Low Fire	High Fire	Min	Max
	Natural	1.7	3.5	4.5	10.5
All Sizes
	LP/propane	4.9	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 18

LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes

	Natural to	High Altitude	High Altitude
		Natural Burner	LP/Propane Burner	High Altitude Pressure Switch
EL296	LP/Propane
		Orifice Kit	Orifice Kit
Unit
	0 - 7500 ft	7501 - 10,000 ft	7501 - 10,000 ft	4501 - 7500 ft	7501 -10,000 ft
	(0 - 2286m)	(2286 - 3038m)	(2286 - 3038m)	(1373 - 2286m)	(2286 - 3048m)
-045				93W81	93W84
-070				93W80	93W85
-090	*78W93	73W37	*78W96	93W82	93W80
-110				93W80	93W85
-135				93W83	93W85

* 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).

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