Lennox SL280DF070V36A, Unit Information

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Page 37
B-Heating Start-Up
WARNING
Shock and burn hazard.
SL280DFV units are equipped with a hot surface
ignition system. Do not attempt to light manually.
1 - STOP! Read the safety information at the beginning
of this section.
2 - Set the thermostat to the lowest setting
3 - Turn off all electrical power to the unit.
4 - This furnace is equipped with an ignition device
which automatically lights the burners. Do not try to
light the burners by hand.
5 - Remove the upper access panel.
6 - Turn switch on gas valve to OFF. Do not force. See
FIGURE 17 or FIGURE 18.
7 - Wait five minutes to clear out any gas. If you then
smell gas, STOP! Immediately call your gas supplier
from a neighbor’s phone. Follow the gas supplier’s
instructions.
8 - If you do not smell gas go to next step.
GAS VALVE SHOWN IN ON POSITION
INLET PRESSURE POST
HIGH FIRE ADJUSTMENT
SCREW
(under cap)
MANIFOLD
PRESSURE TAP
WHITE RODGERS GAS VALVE
LOW FIRE ADJUSTMENT
SCREW
(under cap)
FIGURE 17
GAS VALVE SHOWN IN ON POSITION
MANIFOLD
PRESSURE
TAP ON
SIDE
HIGH FIRE
ADJUSTING SCREW
(under cap)
INLET PRESSURE TAP
ON SIDE
Resideo Two-Stage Gs Valve
FIGURE 18
9 - Turn switch on gas valve to ON. Do not force. See
FIGURE 17 or FIGURE 18.
10 - Replace the upper access panel.
11 - Turn on all electrical power to to the unit.
12 - 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.
Turning Off Gas To Unit
1 - Set thermostat to lowest setting.
2 - Turn off all electrical power to unit if service is to be
performed.
3 - Remove access panel.
4 - Turn switch on gas valve to
OFF. Do not force. See
FIGURE 17 or FIGURE 18.
5 - Replace 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 or tripped circuit breaker?
5 - Is the filter dirty or plugged? Dirty or plugged filters
will cause the limit control to shut the unit off.
6 - Is gas turned on at the meter?
7 - Is the manual main shut-off valve open?
8 - Is the internal manual shut-off valve open?
9 - Is the unit ignition system in lock out? If the unit locks
out again, call the service technician to inspect the
unit for blockages.
10 - Is pressure switch closed? Obstructed flue will
cause unit to shut off at pressure switch. Check flue
and outlet for blockages.
11 - Are flame rollout switches tripped? If flame rollout
switches are tripped, call the service technician for
inspection.
C-Safety or Emergency Shutdown
Turn off unit power. Close manual and main gas valves.
D-Extended Period Shutdown
Turn off thermostat or set to “UNOCCUPIED” mode. Close
all gas valves (both internal and external to unit) to guar-
antee no gas leak into combustion chamber. Turn off pow-
er to unit. All access panels and covers must be in place
and secured.