Proper Gas Flow (Approximate); Proper Combustion; Manifold Adjustment Procedure; Gas Meter Clocking Chart - Lennox G60UHV Service Manual

TABLE 29
All G60UHV Units
Line Pressure WC"
Manifold Pressure High
Heat WC"
Manifold Pressure Low
Heat WC"
IMPORTANT
For safety, connect a shut-off valve between the
manometer and the gas tap to permit shut off of
gas pressure to the manometer.
The gas valve is factory set and should not require adjust-
ment. All gas valves are factory regulated.

Manifold Adjustment Procedure:

1 − Connect a test gauge to manifold pressure tap on gas
valve. See figure 18 or 19 for tap location. Start unit and
allow 5 minutes for unit to reach steady state.
2 − While waiting for the unit to stabilize, notice the flame.
Flame should be stable and should not lift from burner.
Natural gas should burn blue. L.P. gas should burn
mostly blue with some orange streaks.
3 − After allowing unit to stabilize for 5 minutes, record
manifold pressure.
NOTE−Shut unit off and remove manometer as soon as
an accurate reading has been obtained. Take care to re-
place pressure tap plug.
F− Proper Gas Flow (Approximate)
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 30 below. If manifold pressure matches table 29
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 30

GAS METER CLOCKING CHART

Seconds for One Revolution
Natural
G60UH
Unit 1 cu ft
Dial
−70 55
−90 41
−110 33
−135 27
Natural−1000 btu/cu ft
Natural LP
4.5 − 10.5 11.0 − 13.0
3.5 10.0
1.7 4.9
LP
2 cu ft 1 cu ft 2 cu ft
Dial Dial DIAL
110 136 272
82 102 204
66 82 164
54 68 136
LP−2500 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.
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 and compare to the tables below.
The maximum carbon monoxide reading should not ex-
ceed 100 ppm.
Unit
G60UHV−36A−070(X)
G60UHV−36B−090
G60UHV−60C−090(X)
G60UHV−60C−110(X)
G60UHV−60D−135
Unit
G60UHV−36A−070(X)
G60UHV−36B−090
G60UHV−60C−090(X)
G60UHV−60C−110(X)
G60UHV−60D−135
Page 34
TABLE 31
High Heat
CO % CO %
2 For Nat 2
7.2 − 8.2 8.0 − 9.0
7.5 − 8.5 8.5 − 9.5
7.5 − 8.5 8.5 − 9.5
7.3 − 8.3 8.5 − 9.5
7.5 − 8.5 8.8 − 9.8
TABLE 32
Low Heat
CO % CO %
2 For Nat 2
4.2 − 5.2 5.0 − 6.0
4.7 − 5.7 5.0 − 6.0
4.5 − 5.5 5.0 − 6.0
4.5 − 5.5 5.3 − 6.3
4.7 − 5.7 5.8 − 6.8
For L.P.
For L.P.