Lennox SL280UHV series - Installation; Start up

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II-PLACEMENT AND INSTALLATION
Make sure unit is installed in accordance with installation
Instructions and applicable codes.
III-START-UP
A-Preliminary and Seasonal Checks
1 - Inspect electrical wiring, both eld and factory installed
for loose connections. Tighten as required.
2 - Check voltage at disconnect switch. Voltage must be
within range listed on the nameplate. If not, consult the
power company and have voltage condition corrected
before starting unit.
B-Heating Start-Up
WARNING
Shock and burn hazard.
SL280UHV 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 o󰀨 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 19 and FIGURE 20.
7 - Wait ve 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 19
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 20
9 - Turn switch on gas valve to ON. Do not force. See
FIGURE 19 or FIGURE 20.
10 - Replace the upper access panel.
11 - Turn on all electrical power 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 O󰀨 Gas To Unit
1 - Set thermostat to lowest setting.
2 - Turn o󰀨 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 19 or FIGURE 20.
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 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 internal manual shut-o󰀨 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 ue will
cause unit to shut o󰀨 at pressure switch. Check ue
and outlet for blockages.
11 - Are ame rollout switches tripped? If ame rollout
switches are tripped, call the service technician for
inspection.