Lennox International Inc ML193UH Proper Combustion, High Altitude Information, Unit

Proper Combustion

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 12

ML193	CO2% For Nat	CO2% For L.P.
Unit
-045
-070
-090	7.2 - 7.9	8.6 - 9.3
-110
-135

The maximum carbon monoxide reading should not exceed 50 ppm.

High Altitude Information

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

ML193UH units require no manifold pressure adjustments for operation at altitudes up to 10,000 feet (3048 m) above sea level. Units installed at altitude of 4501 - 10,000 feet (1373 to 3048m) require a pressure switch change which can be ordered separately. Table 13 lists conversion kit and pressure switch requirements at varying altitudes.

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

NOTE - A natural to LP/propane gas changeover kit is nec­ essary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.

TABLE 13

Conversion Kit and Pressure Switch Requirements at Varying Altitudes

	Natural to	High Altitude	LP/Propane	High Altitude
		Natural Burner	to	LP/Propane	High Altitude Pressure Switch
ML193	LP/Propane
		Orifice Kit	Natural	Burner Orifice Kit
Unit
	0 - 7500 ft	7501 - 10,000 ft	0 - 7500 ft	7501 - 10,000 ft	4501 - 7500 ft	7501 -10,000 ft
	(0 - 2286m)	(2286 - 3038m)	(0 - 2286m)	(2286 - 3038m)	(1373 - 2286m)	(2286 - 3048m)
-045
-070
-090	*69W73	73W37	*73W81	*68W68	93W87	93W88
-110
-135

* 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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