Lennox SIGNATURE SLP99DFV User Manual

Page 51
9 - Replace the access panel.
10 - Turn on all electrical power to to the unit.
11 - Set the thermostat to desired setting.
NOTE - When unit is initially started, steps 1 through 11
may need to be repeated to purge air from gas line.
12 - If the appliance will not operate, follow the
instructions “Turning O󰀨 Gas to Unit” and call the
gas supplier.
Turning O󰀨 Gas to Unit
1 - Set the thermostat to the lowest setting.
2 - Turn o󰀨 all electrical power to the unit if service is to
be performed.
3 - Remove the access panel.
4 - Move the gas valve switch to the OFF position.
5 - Replace the access panel.
Failure To Operate
If the unit fails to operate, check the following:
1 - Is the thermostat calling for heat?
2 - Are access panels securely in place?
3 - Is the main disconnect switch closed?
4 - Is there a blown fuse?
5 - Is the lter dirty or plugged? Dirty or plugged lters
will cause the limit control to shut the unit o󰀨.
6 - Is gas turned on at the meter?
7 - Is the manual main shut-o󰀨 valve open?
8 - Is the gas valve turned on?
9 - Is the unit ignition system in lock out? If the unit
locks out again, inspect the unit for blockages.
10 - Is blower harness connected to ignition control?
Furnace will not operate unless harness is
connected.
High Altitude Information
NOTE - In Canada, certication for installations at eleva-
tions over 4500 feet (1372 m) is the jurisdiction of local
authorities.
SLP99DFV units require no manifold pressure adjust-
ments for operation at altitudes up to 10,000 feet (3048
m) above sea level. Units installed at altitude of 7,501 to
10,000 feet (2287 to 3048m) require a pressure switch
change and conversion kit. See TABLE 31.
The combustion air pressure switch is factory-set and re-
quires no adjustment.
Gas Pressure Measurement
Gas Flow (Approximate)
TABLE 28
GAS METER CLOCKING CHART
SLP99
Unit
Seconds for One Revolution
Natural LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-070 55 110 136 272
-090 41 82 102 204
-110 33 66 82 164
-135 27 54 68 136
Natural-1000 btu/cu ft LP-2500 btu/cu ft
Furnace should operate at least 5 minutes before check-
ing gas ow. 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 28. If manifold pressure matches TABLE 28 and
rate is incorrect, check gas orices for proper size and
restriction. Remove temporary gas meter if installed.
NOTE - To obtain accurate reading, shut o all other gas
appliances connected to meter.
Supply Pressure Measurement
A threaded plug on the inlet side of the gas valve provides
access to the supply pressure tap. Remove the thread-
ed plug, install a eld-provided barbed tting and connect
a manometer to measure supply pressure. Replace the
threaded plug after measurements have been taken.
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas ow rate before checking com-
bustion. Take combustion sample beyond the ue outlet
and compare to the tables below. The maximum carbon
monoxide reading should not exceed 100 ppm.
TABLE 29
High Fire
SLP99DFV Unit
6.5 - 9.0 7.7 - 10.2
070
090
110
TABLE 30
Low Fire
SLP99DFV Unit
4.7 - 7.2 5.7 - 8.2
070
090
110

Lennox SIGNATURE SLP99DFV Specifications

General

Brand	Lennox
Model	SIGNATURE SLP99DFV
Category	Furnace
Language	English