Page 11
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
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)
R 0-1
0V W
(+) INPUT (-)
LWC
O/S
T/T
AC24V
OUTPUT
DHW
TEMPERATURE
SENSOR
DHW
P
UM
P
N
G
L
N
G
SYSTEM
P
UM
P
L
N
G
MAIN POWER
L/ZC
L-T/T
P
UM
P
N
G
L/ZC
L-T/T
CASCADE
SYSTEM
SENSOR
INPU
T
1
2
0
V
OL
T
C
IRCULA
T
OR
S
X
X
E
N
D
S
W
IT
C
H
Z
C
1
2
0
V
RE
L
A
Y
FU
S
E
1
AM
P
SL
A
V
E
MA
S
TE
R
1
23
4
Z
O
NE
4
PR
IOR
IT
Y
O
N
OF
F
PO
W
E
R
ZO
N
E
2
ZO
N
E
3
FOU
R
ZONE
S
W
ITC
H
IN
G
RELA
Y
W
ITH OPT
IO
N
AL PR
IOR
IT
Y
PL
U
G-
IN CAR
D
S
R
E
SET N
O
RMA
L
S
R
5
0
4
-E
X
P
T
'S
T
AT
S
ZO
N
E
1
ZONE
3
PO
W
E
R
ZONE
1
ZONE
2
Z
R
Wiring Diagram for Cascaded
Reverse Return with Zone Pumps
Floor M
odel B
oiler 1 (L
ead)
Floor M
odel B
oiler 2 (F
ollo
w)
P3
P2
P1
Outdoor
Sensor
(18 Gauge Wire)
Line
V
oltage T
erminals
Low
V
oltage T
erminals
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
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
(14 Gauge Wire)
Optional External
Low W
ater Cutof
f
(Factory Jumper Installed)
Optional External
Low W
ater Cutof
f
(Factory Jumper Installed)
NOTE: The terminal blocks ar
e NOT the same on
the floorstanding VS the wall-mounted models!
See Section 1.D on page 5
Generic Pump Controller
Figure 11.
Wiring diagram for cascaded reverse return with zone pumps.
