Filter
Top Products
6
BCP-3 Installation and Operation Manual
T1
T2
COM
COM
T3+
T3-
EXT+
EXT-
P+
P-
COM
24VAC
System Sensor
Outdoor Sensor
Enable Dry Contact
Setback Timer
120 VAC
Wiring 1 Lo/Hi Boiler +
System Pump
System Pump
(Yellow/Output 1)
Boiler Lo
(Blue/
Output 2)
Boiler Hi
(White/
Output 3)
DHW Call
Power (Black)
120 VAC
L
N
L
N
T1
T2
COM
COM
T3+
T3-
EXT+
EXT-
P+
P-
COM
24VAC
System Sensor
Outdoor Sensor
Enable Dry Contact
Setback Timer
Boiler
(Blue/
Output 2B)
Output capped
(White/Output 3)
Wiring 1 On/Off Boiler +
System Pump
DHW Call
Power (Black)
120 VAC
L
N
120 VAC
L
N
System Pump
(Yellow/Output 1)
T1
T2
COM
COM
T3+
T3-
EXT+
EXT-
P+
P-
COM
24VAC
System Sensor
Outdoor Sensor
Enable Dry Contact
Setback Timer
DHW Call
DHW Pump (White/Output 3)
Boiler
(Blue/
output 2)
Wiring 1 On/Off Boiler +
System Pump + DHW Pump
Power (Black)
120 VAC
L
N
System Pump
(Yellow/Output 1)
120 VAC
L
N
T1
T2
COM
COM
T3+
T3-
EXT+
EXT-
P+
P-
COM
24VAC
System Sensor
Outdoor Sensor
Enable Dry Contact
Setback Timer
Wiring 2 On/Off Boilers +
System Pump
Boiler1
(Blue/
Output 2)
Boiler2
(White/
Output 3)
DHW Call
Power (Black)
120 VAC
L
N
120 VAC
L
N
System Pump
(Yellow/Output 1)
T1
T2
COM
COM
T3+
T3-
EXT+
EXT-
P+
P-
COM
24VAC
System Sensor
Outdoor Sensor
Enable Dry Contact
Setback Timer
Wiring 3 On/Off Boilers
Boiler 2
(Blue/
Output 2)
Boiler 3
(White/
Output 3)
Boiler 1
(Yellow/
Output 1)
DHW Call
Power (Black)
120 VAC
L
N
Boiler
SYS
Pump
DHW
Pump
SET
SET
SYSTEM = 147F
TARGET = 150F
Boiler
SYS
Pump
DHW
Pump
SET
SET
SYSTEM = 147F
TARGET = 150F
Boiler
SYS
Pump
DHW
Pump
SET
SET
SYSTEM = 147F
TARGET = 150F
Boiler
SYS
Pump
DHW
Pump
SET
SET
SYSTEM = 147F
TARGET = 150F
Boiler
SYS
Pump
DHW
Pump
SET
SET
SYSTEM = 147F
TARGET = 150F
BCP-3
BCP-3 BCP-3
BCP-3BCP-3
Output 1 Output 2 Output 3 Output 1 Output 2 Output 3
Output 1 Output 2 Output 3 Output 1 Output 2 Output 3
Output 1 Output 2 Output 3
BCP-3 Output Modes Wiring
NOTES:
• The BCP-3 does not source any output power
to any of its relays. A power source must sup-
ply the pumps with power and the control can
break the hot leg.
• Weil McLain recommends not sharing the
power source to the control with any pumps,
boilers, or heavy electric equipment.
• When wiring a sensor to the BCP-3, connect
the Shield to the COM terminal on the BCP-3
end. DO NOT connect the Shield at the sensor
end.
• Eventhough in some Output Modes the BCP-3
does not control the DHW Pump, a DHW call
will raise the System Target to whichever is
lower of 200F or the Maximum Water Temp.