Lennox G60UHV Series Installation Instructions Manual page 38

12- Iftheappliance w illnotoperate, follow theinstructions
"Turning O ffGastoUnit"andcallyourservice techni-
cian
or gas supplier.
Turning Off Gas to Unit
1 - Set the thermostat to the lowest setting,
2 - Turn off all electrical power to the unit if service is to be
performed,
3 - Remove the upper access panel.
4 - White Rodgers 36E Gas Valve- Switch gas valve le-
verto OFF.
Honeywell VR8205 Gas Valve - Turn knob on gas
valve clockwise _ll to OFF, Do not force,
5 - Replace the upper access panel,
Gas Flow
To check for proper gas flow to the combustion chamber,
determine the Btu (kW) input from the unit nameplate, Di-
vide this input rating by the Btu (kW) per cubic foot (cubic
meter) of available gas, The result is the required number
of cubic feet (cubic meter) per hour. Determine the flow of
gas through the gas meter for two minutes and multiply by
30 to get the hourly flow of gas,
Gas Pressure
1 - Check the gas line pressure with the unit firing at maxi-
mum rate, A minimum of 4,5 in, w,c, for natural gas or
11,0 in, w,c, for LP/propane gas should be maintained,
2- After the line pressure has been checked and ad-
justed, check the low fire and high fire manifold pres-
sures, See figures 26 and 27 for the location of the
manifold pressure adjustment screws. Low and high
fire manifold pressures are given in table 29, A natural
gas to LP/propane gas changeover kit is required to
convert the unit,
Refer to table 29 for high altitude requirements and man-
ifold pressure settings at all altitudes.
NOTE - In Canada, certification for installations at eleva-
tions over 4500 feet (1372 m) is the jurisdiction of local au-
thorities.
NOTE - A natural to L.P. propane gas changeover kit is nec-
essary to convert this unit. Refer to the changeover kit
installation instruction for the conversion procedure.
Primary and Secondary Limits
The primary limit is located on the heating compartment
vestibule panel. The secondary limits (if equipped) are lo-
cated in the blower compartment, attached to the back side
of the blower, These limits are factory set and require no
adjustment.
Flame Rollout Switches (Two)
These manually reset switches are located on (or inside of)
the burner box, If tripped, check for adequate combustion
air before resetting.
Pressure Switches
The pressure switch assembly (includes two switches) is
located in the heating compartment adjacent to the com-
bustion air inducer. These switches check for proper com-
bustion air inducer operation before allowing ignition trial,
The switches are factory-set and require no adjustment,
Temperature Rise
Place the unit into operation with a second-stage heating
demand. After supply and return air temperatures have
stabilized, check the temperature rise. If necessary, adjust
the heating blower speed to maintain the temperature rise
within the range shown on the unit nameplate, Increase the
blower speed to decrease the temperature rise, Decrease
the blower speed to increase the temperature rise. Failure
to properly adjust the temperature rise may cause erratic
limit operation,
Thermostat Heat Anticipation
Set the heat anticipator setting (if adjustable) according to
the amp draw listed on the wiring diagram that is attached
to the unit,
TABLE 29
High Altitude Requirements / Manifold Pressure Settings
Model
Input
Size
Gas
0 - 4500 ft.
(0 - 1372 m)
Required
Conversion Pressure
Kit Switch
Altitude
4,501 - 7500 ft.
(1373 - 2286 m)
Required
Conversion Pressure
Kit Switch
7501-10,000 ft.
(2286 - 3048 m)
Required
Conversion Pressure
Kit Switch
Manifold Pressure
at all altitudes
in. w.g. kPa in. w.g.
Nat. N/A No Change N/A No Change 59M16 18M64 1.7 0.42 3.5
-070
LPG 59M13" No Change 59M13" No Change 59M14" 18M64 4.9 1.22 10.0
Nat, N/A No Change N/A 18M61 59M16 18M64 1.7 0.42 3.5
-090
LPG 59M13" No Change 59M13" 18M61 59M14" 18M64 4.9 1.22 10.0
-110 Nat. N/A No Change N/A 18M63 59M16 18M61 1.7 0.42 3.5
-135 LPG 59M13" No Change 59M13" 18M63 59M14" 18M61 4.9 1.22 10.0
Low Fire High Fire
kPa
0.87
2.5
0.87
2.5
0.87
2.5
Pressure switch is factory set. No adjustment necessary. All models use the factory installed pressure switch from 0-4500 feet (0-1370 m).
*LPG/Propane conversion kit includes LP regulator.
Page 38