44
8 - ELECTRICAL CONNECTIONS
A. Connect 24V Heat Call
•
turn power off to boiler;
• access terminal block
M2
;
• Dry contact 6(R)-7(W)-8(C) heat call connection.
• turn boiler power on;
• verify room thermostat operates per thermostat
manufacturer instructions.
NOTE:
maximum load allowed is 10 mA
FIGURE 8-4 THERMOSTAT CONNECTIONS
8.5 Install Room Thermostat
Install room thermostat on inside wall. Do not install where it
will be influenced by drafts, hot or cold water pipes, lighting
fixtures, television, sun rays or near a fireplace.
Dry contact only - do not apply 24 volts between 6 and 7.
A
24V Thermostat
Call From Zone
Control Board
FIGURE 8-5 HEAT ONLY BOILER WITH INDIRECT ZONE PUMP, DHW TANK, TANK T-STAT W/ STANDARD ZONE
CONTROL BOARD
ZONE 1
LINE
115 Vac
N
L 1
ZR
ZC
N
L
3
N
L
2
115 Vac
N
L
1
L
N
ZONE PUMPS
X
X
X
X
X
3
2
1
X
NE
C Class
2 Low
Vol
tage
ZONE 3
ZONE 2
ZONE 1
W
R
NEC Class 2 Low Voltage
T
T C
THERMOSTATS
ZONE VALVES
ZONE 3
ZONE 2
4
3
2
1
4
3
2
1
4
3
2
1
NEC Class 2 Low Voltage (24Vac)
W
R
T
T C
W
R
T
T C
PRI PUMP
ZC/ZR
Fuse
12A 250V
9
10
6
7
N
G
L
PUMP
DOMESTIC HOT
WATER TANK
W/ T-STAT
ZONE
THERMOSTAT
115 Vac FIELD
SUPPLIED POWER
PER NEC. AND
LOCAL CODES
6 & 7 = CH
9 & 10 = DHW TANK
BOILER
DHW Z2
115 Vac FIELD
SUPPLIED POWER
PER NEC. AND
LOCAL CODES
Z2
ZONE 1
LINE
115 Vac
N
L 1
ZR
ZC
N
L
3
N
L
2
115 Vac
N
L
1
L
N
ZONE PUMPS
X
X
X
X
X
3
2
1
X
NE
C Cl
as
s 2 Lo
w
Vo
lta
ge
ZONE 3
ZONE 2
ZONE 1
W
R
NEC Class 2 Low Voltage
T
T C
THERMOSTATS
ZONE VALVES
ZONE 3
ZONE 2
4
3
2
1
4
3
2
1
4
3
2
1
NEC Class 2 Low Voltage (24Vac)
W
R
T
T C
W
R
T
T C
PRI PUMP
ZC/ZR
Fuse
12A 250V
9
10
6
7
N
G
L
PUMP
FIGURE 8-6 COMBI BOILER WITH STANDARD ZONE CONTROL
BOILER
115 Vac FIELD
SUPPLIED POWER
PER NEC. AND
LOCAL CODES
6 & 7 = CH
ZONE
THERMOSTAT
115 Vac FIELD
SUPPLIED POWER
PER NEC. AND
LOCAL CODES
M2 Block
M2 Block
PN 240012363 REV. B [03/29/2019]
