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A
B
C
FIGURE 33
IGNITOR AND SENSOR POSITION
TOP VIEW
SIDE VIEW IGNITOR
SIDE VIEW SENSOR
1-3/4”
(45mm)
3/8”
(10mm)
1-3/8”
(35mm)
BURNER BOX
Gas Flow
Gas Flow
13/16”
(21mm)
A
B
C
IGNITOR
SENSOR
TABLE 15
Dimension
Unit
Btuh Input
Length - in. (mm)
Ignitor
Sensor
A
130K
7-3/4 (197)
11 (279)
B
180K
5 (127)
5-1/2 (140)
C
240K
2-1/4 (57)
2-3/4 (70)
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.
WARNING
Danger of explosion. Can cause injury
or death. Do not overtighten main
burner mounting screws. Snug tighten
only.
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. With power supply
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 pressure switch air tubing from
combustion air inducer port.
3- Remove and retain screws securing combustion air
inducer to flue box. Remove vent connector. See
figure 34.
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.
HEAT EXCHANGER ASSEMBLY
FIGURE 34
BURNER
COMBUSTION
AIR INDUCER
VENT
CONNECTOR
GAS VALVE
HEAT
EXCHANGER
TUBE
