Manifold Pressure Check Set Up; Proper Gas Flow; Proper Combustion; High Altitude - Lennox EL296UH045XE36B Unit Information

5/16" Round
Hose
Reducer
Fitting
F- Proper Gas Flow (Approximate)
Furnace should operate at least 5 minutes before checking
gas flow. Determine time in seconds for two revolutions of
gas through the meter. (Two revolutions assures a more
accurate time.) Divide by two and compare to time in table
21 below. If manifold pressure matches table 21 and rate is
incorrect, check gas orifices for proper size and restriction.
NOTE- To obtain accurate reading, shut off all other gas
appliances connected to meter.
TABLE 21
GAS METER CLOCKING CHART
Seconds for One Revolution
Natural
EL296
Unit
1 cu ft 2 cu ft
Dial
-045 80
-70 55
-90 41
-110 33
-135 27
Natural-1000 btu/cu ft
IMPORTANT
For safety, shut unit off and remove manometer as
soon as an accurate reading has been obtained.
Take care to replace pressure tap plug.

MANIFOLD PRESSURE CHECK SET UP

Manifold Post
Clamp
10" Long
Square
Tubing
LP
1 cu ft 2 cu ft
Dial Dial DIAL
160 200 400
110 136 272
82 102 204
66 82 164
54 68 136
LP-2500 btu/cu ft
2" Long
Square Tubing
Tee
Measuring Device
FIGURE 52
G- Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas flow rate before checking com­
bustion. See sections E- and F-. Take combustion sample
beyond the flue outlet. Table 22 shows acceptable com­
bustions. The maximum carbon monoxide reading should
not exceed 50 ppm.
EL296
Model
Low Fire
045 5.4 - 6.4
070 5.3 - 6.3
090 5.8 - 6.8
110 6.1 - 7.1
135 6.1 - 7.1
The maximum carbon monoxide reading should not exceed 50 ppm.
H- High Altitude
The manifold pressure, gas orifice and pressure switch
may require adjustment or replacement to ensure proper
operation at higher altitudes. See table 23 or 24 for man­
ifold pressures and table 25 for gas conversion and pres­
sure switch kits.
Page 46
Gas Valve Regulator
Vent Hose
(to burner box)
TABLE 22
CO % CO
2 For Nat
High Fire Low Fire
7.5 - 8.5 6.4 - 7.4
7.4 - 8.4 6.3 - 7.3
7.6 - 8.6 6.8 - 7.8
8.0 - 9.0 7.1 - 8.1
7.8 - 8.8 7.1 - 8.2
%
2 For L.P
High Fire
8.8 - 9.8
8.7 - 9.7
8.9 - 9.9
9.3 - 10.3
9.1 - 10.1