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E-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 table 17.
TABLE 17
ML193
Unit
CO
2
%
For Nat
CO
2
%
For L.P.
-030
6.5 - 7.5
7.5 - 8.5
-045
7.0 - 9.0
8.0 - 10.0
-070
-090
-110
The maximum carbon monoxide reading should not exceed 100 ppm.
F-High Altitude
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. See table 18 for de-rate manifold values. Units
installed at altitude of 7501 - 10,000 feet require an orifice
change. Units installed at altitude of 4501 - 10,000 feet re
quire a pressure switch change which can be ordered sep
arately. Table 19 lists conversion kit and pressure switch re
quirements 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 in
stallation instruction for the conversion procedure.
TABLE 18
Manifold and Supply Line Pressure 0-10,000ft.
ML193E
Unit
Gas
Manifold Pressure in. wg.
Supply Line Pressure
in. w.g.
0 - 10000 ft.
0-4500 ft.
4501-5500 ft.
5501-6500 ft.
6501 - 7500ft.
7501 - 10000ft.
All Sizes
Natural
3.5
3.3
3.2
3.1
3.5
4.5
13.0
LP/propane
10.0
9.4
9.1
8.9
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 19
Conversion Kit and Pressure Switch Requirements at Varying Altitudes
ML193E
Unit
Natural to
LP/Propane
High Altitude
Natural Burner
Orifice Kit
LP/Propane
to
Natural
High Altitude
LP/Propane
Burner Orifice Kit
High Altitude Pressure Switch
0 - 7500 ft
(0 - 2286m)
7501 - 10,000 ft
(2286 - 3038m)
0 - 7500 ft
(0 - 2286m)
7501 - 10,000 ft
(2286 - 3038m)
4501 - 7500 ft
(1373 - 2286m)
7501 -10,000 ft
(2286 - 3048m)
-030
17H63
14C90
N/A
17H66
11U65
11U66
-045
*11K49
73W37
*73W81
*11K44
-070
-090
-110
* 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).