EL280UH Two-Stage Gas Furnace Installation Manual - Lennox

TABLE 14
Manifold Pressure Settings at all Altitudes
Unit
Input
070
090
110
135
Gas
Manifold
Pressure in.wg.
0−4500 ft.
Manifold
Pressure in.wg.
4501−7500 ft. 1
Supply Line
Manifold
7501 − 10,000 ft. 2 in. w.g.
Pressure in.wg. Pressure
Low Fire High Fire Low Fire High Fire Low Fire High Fire Min Max
Natural 1.7 3.5 1.6 3.4 1.7 3.5 4.5 13.0
LP/propane 3 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0
Natural 1.7 3.5 1.5 3.2 1.7 3.5 4.5 13.0
LP/propane 3 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0
Natural 1.7 3.5 1.5 3.2 1.7 3.5 4.5 13.0
LP/propane 3 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0
Natural 1.7 3.5 1.5 2.8 1.7 3.5 4.5 13.0
LP/propane 3 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0
1 This is the only permissible derate for these units.
2 Natural gas high altitude orifice kit required.
3 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.
NOTE − Units may be installed at altitudes up to 4500 ft. above sea level without modifications.
Unit
Input
070
TABLE 15
Pressure Switch and Gas Conversion Kits at all Altitudes
High Altitude Pressure Switch Kit
High Altitude
Natural Gas Kit
LP/Propane Gas Kit
LP/Propane to
Natural Kit
0 − 4500 ft. 4501 − 7500 ft. 7501 − 10,000 ft. 7501 − 10,000 ft. 0 − 7500 ft 7501 − 10,000 ft. 0 − 7500 ft.Min
91W53
73W35
090 91W53 73W35
No Change
110 91W53 73W35
135 73W33 73W34
73W37 77W07 77W11 77W09
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.
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