Lennox LCH036 Installation Instructions Manual page 92

C-Burners (Gas Units)
Periodically examine
appearance during the heating season. Before each
heating season examine the burners for any deposits or
blockage which may have occurred.
Clean burners as follows:
1- Turn off both electrical power and gas supply to unit.
2- Remove burner compartment access panel.
3- Remove two screws securing burners to burner
support and lift the burners from the orifices. See
figure 32. Clean as necessary.
4- Locate the ignitor under the left burners. Check
ignitor spark gap with appropriately sized twist drills
or feeler gauges. See figure 33.
GAS
BURNER BOX ASSEMBLY
VALVE
BURNERS
GAS MANIFOLD
FIGURE 32
SPARK GAP
SHOULD BE 1/8"
(3mm)
FIGURE 33
burner flames for
FLAME
SENSOR
IGNITOR
5- Check the alignment of the ignitor and the sensor as
shown in figure 34 and table 29.
proper
6- Replace burners and screws securing burner.
7- Replace access panel.
8- Restore electrical power and gas supply. Follow
lighting instructions attached to unit and use
inspection port in access panel to check flame.
Dimension
A
B
C
D-Combustion Air Inducer (Gas Units)
A combustion air proving switch checks combustion air
inducer operation before allowing power to the gas
controller. Gas controller will not operate if inducer is
obstructed.
Under normal operating conditions, the combustion air
inducer wheel should be checked and cleaned prior to the
heating season. However, it should be examined
periodically during the heating season to establish an
ideal cleaning
disconnected, the condition of the inducer wheel can be
determined by looking through the vent opening.
Clean combustion air inducer as follows:
1- Shut off power supply and gas to unit.
2- Disconnect
combustion air inducer port.
3- Remove and retain screws securing combustion air
inducer to flue box. Remove vent connector. See
figure 35.
4- Clean inducer wheel blades with a small brush and
wipe off any dust from housing. Clean accumulated
dust from front of flue box cover.
5- Return combustion air inducer motor and vent
connector to original location and secure with
retained screws. It is recommended that the
combustion air inducer gasket be replaced during
reassembly.
6- Clean combustion air inlet louvers on heat access
panel using a small brush.
Page 42
TABLE 29
Length - in. (mm)
Unit
Btuh Input
Ignitor
130K 7-3/4 (197)
180K 5 (127)
240K 2-1/4 (57)
WARNING
Danger of explosion. Can cause injury or
death. Do not overtighten main burner
mounting screws. Snug tighten only.
schedule. With
pressure switch
Sensor
11 (279)
5-1/2 (140)
2-3/4 (70)
power supply
air tubing from