Lennox ML196DF045XE36B Manual page 42

F- Proper Gas Flow (Approximate)
Gas Flow (Approximate)
TABLE 17
GAS METER CLOCKING CHART
Seconds for One Revolution
Natural
ML196
Unit 1 cu ft 2 cu ft
Dial
-045 80
-070 55
-090 41
-110 33
Natural-1000 btu/cu ft
NOTE - To obtain accurate reading, shut off all other gas
appliances connected to meter.
Furnace should operate at least 5 minutes before check­
ing gas flow. Determine time in seconds for two revolu­
tions of gas through the meter. (Two revolutions assures a
more accurate time). Divide by two and compare to time
in table 17. If manifold pressure matches table 16 and rate
is incorrect, check gas orifices for proper size and restric­
tion. Remove temporary gas meter if installed.
Conversion Kit and Pressure Switch Requirements at Varying Altitudes
Natural to
LP/Propane
ML196
Unit
0 - 7500 ft
(0 - 2286m)
-045
-070
11K49
-090
-110
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1370 m).
LP
1 cu ft 2 cu ft
Dial Dial DIAL
160 200 400
110 136 272
82 102 204
66 82 164
LP-2500 btu/cu ft
High Altitude
Natural Burner
Orifice Kit
7501 - 10,000 ft
(2286 - 3038m)
73W37
G- Proper Combustion
Furnace should operate at least 15 minutes with correct
manifold pressure and gas flow rate before checking com­
bustions. Take sample beyond the flue outlet and
compare to table 18.
ML196
Unit
-045
-070
-090
-110
The maximum carbon monoxide reading should not exceed 100 ppm.
H- High Altitude
NOTE - In Canada, certification for installations at eleva­
tions over 4500 feet (1372 m) is the jurisdiction of local au­
thorities.
ML196DFE units require no manifold pressure adjust­
ments for operation at altitudes up to 10,000 feet (3048 m)
above sea level. See table 19. However, -4 and later units
installed at altitude of 4501 - 10,000 feet (1373 to 3048m)
may require a pressure switch change which can be or­
dered separately and manifold de-rate. See table 16 for
manifold pressures at varying altitudes. Table 19 lists con­
version kit and pressure switch requirements at varying al­
titudes.
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 19
High Altitude
LP/Propane
Burner Orifice Kit
7501 - 10,000 ft
(2286 - 3038m)
11K44
Page 42
TABLE 18
CO % CO
2 For Nat
7.5 - 8.5
High Altitude Pressure Switch
4501 - 7500 ft 7501 -10,000 ft
(1373 - 2286m) (2286 - 3048m)
11U65
11U70
11U71
17V95
%
2 For LP
8.6 - 9.6
11U66
11U68
11U68
11U67