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LGH/LCH036, 048, 060, 072
WARNING
Danger of explosion. Can cause injury or
death. Do not overtighten main burner
mounting screws. Snug tighten only.
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.
FIGURE 33
BURNER ORIENTATION
150,000 BTUH - 7 BURNERS
108,000 BTUH - 5 BURNERS
65,000 BTUH - 3 BURNERS
SENSOR
IGNITOR
SENSOR
IGNITOR
SENSOR
IGNITOR
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 schedule.
Clean combustion air inducer as follows:
1- Shut off power supply and gas to unit.
2- Remove the mullion on the right side of the heat
section.
3- Disconnect pressure switch air tubing from
combustion air inducer port.
4- Remove and retain screws securing combustion
air inducer to flue box. Remove vent connector.
See figure 34.
5- Clean inducer wheel blades with a small brush and
wipe off any dust from housing. Take care not to
damage exposed fan blades. Clean accumulated
dust from front of flue box cover.
HEAT EXCHANGER ASSEMBLY
FIGURE 34
BURNER
COMBUSTION
AIR INDUCER
VENT
CONNECTOR
GAS VALVE
HEAT
EXCHANGER
TUBE
PRIMARY
LIMIT
ROLLOUT
SWITCH
FLUE BOX
COVER
6- Return combustion air inducer motor and vent
connector to original location and secure with
retained screws. It is recommended that gaskets be
replaced during reassembly.
7- Replace mullion.
8- Clean combustion air inlet louvers on blower access
panel using a small brush.
E-Flue Box (Gas Units)
Remove flue box cover only when necessary for
equipment repair. Clean inside of flue box cover and heat
exchanger tubes with a wire brush when flue box cover
has to be removed. Install a new flue box cover gasket
and replace cover. Make sure edges around flue box
cover are tightly sealed.
F-Evaporator Coil
Inspect and clean coil at beginning of each cooling season.
Clean using mild detergent or commercial coil cleaner.
Flush coil and condensate drain with water taking care not
to get insulation, filters and return air ducts wet.
