Lennox International Inc. G24-200 - Manual (Page 36)

Page 36
Temperature Rise
Check the temperature rise and, if necessary, adjust the
blower speed to maintain the temperature rise within the
range shown on the unit rating plate.
Electro-mechanical Thermostat Heat Anticipation
In single-stage heat applications, set the heat anticipation
to 0.2 amps.
In two-stage heat applications, set the heat anticipation to
0.26 amps and install a field-provided resistor (150 ohm, 10
watt rating −Lennox part number P−8−6256) in parallel with
K13 relay coil.
Electrical
1 − Check all wiring for loose connections.
2 − Check for the correct voltage at the furnace (furnace
operating).
3 − Check amp-draw on blower motor.
Motor service factor amps
Nameplate __________Actual__________
Flue And Chimney
1 − Check flue pipe, chimney and all connections for tight-
ness and to make sure there is no blockage.
2 − Check unit for proper draft.
3 − Are pressure switches closed? Obstructed flue will
open pressure switches and cause unit to shut down.
Check flue and outlet for blockages.
4 − Reset manual flame rollout switches on burner box
covers.
Burner Flame Adjustment
The G24−200 burner flame is not adjustable; however, the
flame should be inspected at the beginning of each heating
season. If necessary, clean the burners. Burner flame
should be blue when burning natural gas. See figure 21.
BURNER FLAME
BURNER
FLAME
HEAT
EXCHANGER
TUBE
VEST
PANEL
FLAME APPEARS
BLUE IF BURNING
NAT. GAS.
FIGURE 21
Failure To Operate
If 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 − Are the filters dirty or plugged? Dirty or plugged filters
will cause the limit controls to shut the unit off.
6 − Is gas turned on at the meter?
7 − Is the manual main shut-off valve open?
8 − Are the internal manual shut-off valves open?
9 − Are the unit ignition systems in lock out mode? If unit
locks out again, call serviceman to inspect unit for block-
ages.