74
14
Diagrams
BOX DEPICTS
OPTIONAL ITEMS
LADDER DIAGRAM
LBL20026 REV A
120 VAC
24 VAC
120VAC
TERMINAL STRIP
120V SUPPLY "L"
X1-6
DHW PUMP
RELAY
BLOWER
RELAY
X1-3
X1-1
DHW
PUMP "L"
DHW
PUMP
DHW
PUMP "N"
1
2
3
BLOWER
JUNCTION BOX
X1-5
X6-8
X6-3
F5
X5-7
X6-7
NEUTRAL
CN2-4
CN2-10
CONNECTION
BOARD
CN2-6
CN5-1
TERMINAL STRIP
120V SUPPLY "N"
JUNCTION
BOX
X1-8
CN5-3
LWCO
CN5-2
CN5-4
CONNECTION
BOARD
CONNECTION
BOARD
CN2-11
CN2-3
X6-9
X6-5
INTEGRATED
CONTROL
MANUAL RESET
HIGH LIMIT
X5-14
CN2-5
X6-4
CONNECTION
BOARD
LOW GAS
PRESSURE
SWITCH
HIGH GAS
PRESSURE
SWITCH
EXTERNAL
LIMIT
CN2-9
X6-10
BLOCKED
DRAIN
SWITCH
AUTO RESET
HI-LIMIT
X5-11
X5-3
X5-10
X5-4
X2-1
GAS VALVE
GAS VALVE
RELAY
X5-5
X5-13
X5-6
X5-12
1
2
4
5
5A
F4
3.5A
F2
3.5A
F3
1.25A
TR1
X1-7
FLAME ROD
SPARK
ROD
INTEGRATED CONTROL
GROUND
JUNCTION BOX
INTEGRATED
CONTROL
120 VAC
LOW VOLTAGE
HIGH VOLTAGE
CAUTION
HIGH VOLTAGE SPARK LEAD
BLOWER
TERMINAL
STRIP
TERMINAL
STRIP
2
1
X2-2
GND
X6-2
CN2-12
NOTES:
1. Where possible, switches are shown without utilities (gas, water or
electricity) connected to the unit. As such, actual switch states may
vary from those shown on diagrams depending upon whether utilities
are connected or a fault condition is present.
2. See wiring diagram for additional notes.
AIR PRESSURE
SWITCH
PUMP
RELAY COIL
2
1
PUMP
RELAY
3
4
CN4-6
CN4-3
CN3-8
CN3-6
CN3-4
CN3-10
DISPLAY
CONNECTION BOARD
INLET
SENSOR
OUTLET
SENSOR
FLUE
SENSOR
X4-8
X4-6
X4-4
X4-10
INTEGRATED
CONTROL
CN4-11
CN4-12
CN4-10
CN4-4
ALARM
CONTACTS
RUN-TIME
CONTACTS
X3-1
X3-3
X3-4
X3-2
X5-8
X5-1
X5-2
X5-9
X3
RIBBON CABLE
X8
TANK
SENSOR
0-10V
+
-
EXTERNAL
CONTROL
5
6
3
4
PC
INTERFACE
S4
S2
S1
S3
CN4-1
CN4-4
CN4-2
CN4-5
Figure 14-1
Ladder Diagram
Installation & Service Manual
TM