Other Unit Adjustments - Lennox ELITE Series Installation Instructions Manual

Other Unit Adjustments

NOTE − See troubleshooting flow charts if any safety
switches are found to be open.
Primary Limit.
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no ad-
justment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of
the burner box.
Pressure Switch
The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory−set and must not be adjusted.
Temperature Rise
After the furnace has been started and supply and return air
temperatures have been allowed to stabilize, check the
temperature rise. If necessary, adjust the blower speed to
maintain the temperature rise within the range shown on
the unit nameplate. Increase the blower speed to decrease
the temperature. Decrease the blower speed to increase
the temperature rise. Failure to adjust the temperature rise
may cause erratic limit operation.
Fan Control
Fan On Delay
The heat fan on time of 30 seconds is not adjustable. The
cool fan on delay is 2 seconds and not adjustable.
Fan Off Delay
The heat fan off delay (amount of time that the blower oper-
ates after the heat demand has been satisfied) may be ad-
justed by changing the jumper position across the five pins
on the integrated control. The unit is shipped with a factory
fan off setting of 90 seconds. The fan off delay affects com-
fort and is adjustable to satisfy individual applications. Ad-
just the fan off delay to achieve a supply air temperature be-
tween 90° and 110°F at the moment that the blower is
de−energized. Longer off delay settings provide lower re-
turn air temperatures; shorter settings provide higher re-
turn air temperatures. See figure 60.
The cool fan off delay (amount of time that the blower oper-
ates after the cool demand has been satisfied) is 45 sec-
onds and not adjustable.
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.
Electrical
1 − Check all wiring for loose connections.
2 − Check for the correct voltage at the furnace (furnace
operating). Correct voltage is 120VAC + 10%
3 − Check amp−draw on the blower motor with blower ac-
cess panel in place.
Motor Nameplate__________Actual__________
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HEAT FAN-OFF TIME IN SECONDS
NO JUMPER
To adjust fan−off timing, reposition jumper across pins to
achieve desired setting.
60 Second 90 Second
off Time off Time
Blower Speeds
Follow the steps below to change the blower speeds.
1 − Turn off electrical power to furnace.
2 − Remove blower access panel.
3 − Disconnect existing speed tap at integrated control
speed terminal.
NOTE − Termination of any unused motor leads must be
insulated.
4 − Place unused blower speed tap on integrated control
PARK" terminal or insulate.
5 − Refer to blower speed selection chart on unit wiring dia-
gram for desired heating or cooling speed. See Blower
performance data beginning on the next page.
6 − Connect selected speed tap at integrated control
speed terminal.
7 − Resecure blower access panel.
8 − Turn on electrical power to furnace.
9 − Recheck temperature rise.
Electronic Ignition
The integrated control has an added feature of an internal
Watchguard control. The feature serves as an automatic re-
set device for integrated control lockout caused by ignition
failure. This type of lockout is usually due to low gas line
pressure. After one hour of continuous thermostat demand
for heat, the Watchguard will break and remake thermostat
demand to the furnace and automatically reset the inte-
grated control to begin the ignition sequence.
Exhaust and Air Intake Pipe
1 − Check exhaust and air intake connections for tightness
and to make sure there is no blockage.
2 − Is pressure switch closed? Obstructed exhaust pipe
will cause unit to shut off at pressure switch. Check ter-
mination for blockages.
3 − Obstructed pipe or termination may cause rollout
switches to open. Reset manual flame rollout switches
on burner box assembly if necessary.
Page 44
120 Second 180 Second
off Time off Time
FIGURE 60