Page 15
Cascading the FT Series ‘Heating Only’ Boiler
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
AC24V
OUTPUT
DHW
TEMP.
SENSOR
DHW
P
UM
P
N G
L N G
SYSTEM
P
UM
P
Outdoor
Sensor
(18 Gauge Wire)
L N G
MAIN POWER
L/ZC
L-T/T
P
UM
P
N G
L/ZC
L-T/T
CASCADE
SYSTEM
SENSOR
Cascade
System Sensor
(18 Gauge Wire)
Line
V
oltage T
erminals
Low
V
oltage T
erminals
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
AC24V
OUTPUT
DHW
TEMPERATURE
SENSOR
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Low
V
oltage T
erminals
Line
V
oltage T
erminals
Low
V
oltage T
erminals
Low
V
oltage T
erminals
DHW
P
UM
P
N
G
L
N
G
SYSTEM
P
UM
P
L
N
G
MAIN POWER
(14 Gauge Wire)
(14 Gauge Wire)
L/ZC
L-T/T
P
UM
P
N
G
L/ZC
L-T/T
CASCADE
SYSTEM
SENSOR
Wiring Diagram for Cascaded
Reverse Return with Low
T
emp Zones and
Air Handlers
P1
P2
TT1
TT2
Optional External
Low Water Cutoff
(Factory Jumper Installed)
Optional External
Low Water Cutoff
(Factory Jumper Installed)
Floor M
odel B
oiler 1 (L
ead)
Floor M
odel B
oiler 2 (F
ollo
w)
Figure 15.
Wiring diagram for cascaded reverse return with
low temp zones and air handlers.
NOTE: The terminal blocks ar
e NOT the same on
the floorstanding VS the wall-mounted models!
See Section 1.D on page 5
