Room Thermostat Wiring Connections; Outdoor Sensor Connections; Aquastat (Default) And Tank Sensor (Optional) Connections (Non-Combi Models) - NTI FTVN085 Installation Start-Up Maintenance

Part 7 - Connecting Electrical Service
7. Open the control panel cover to have access to the main PCB. See
Figure 51.
Figure 51 - Access to Low Voltage Wiring Connections
Low Voltage Wiring Connections
BUS
Remote Control Connection
TT2
OD
TNK Tank Temperature Sensor (Probe / Aquastat)
SYS
System Sensor (Cascade Manager)
TT1
Table 18 - Low Voltage Wiring Connections
Remote Control (optional)
Outdoor
Sensor
OK
120V
T B
BUS
Figure 52 - Low Voltage Wiring Connections
CAUTION
DO NOT CONNECT 120V TO ANY CONTROL WIRING
CONNECTION! DOING SO WILL RESULT IN IMPROPER
OPERATION AND POSSIBLE DAMAGE TO THE BOILER. SUCH
DAMAGES ARE NOT COVERED BY PRODUCT WARRANTY!
NOTICE
Remove the factory installed jumper from TT1.
50
Room Thermostat 2
Outdoor Sensor
Room Thermostat 1
Tank temp.
probe
System
Sensor
Room Thermostat
1 2 3 4 5
120V 120V 120V 120V 120V
5V IN
TT2 OD TNK SYS TT1

3. Room Thermostat Wiring Connections

To connect a room thermostat:
1. Access the low voltage wiring connections by following the
directions in Item 3, Low Voltage Wiring Connections.
2. Loosen the cable clamp using a screwdriver and insert the wires
leading from the room thermostat.
3. Connect the room thermostat wires to the terminals indicated in
Table 18 and Figure 52.
4. Ensure that the wires are well connected and not subject to stress
when the control panel or cabinet cover are closed.
CAUTION
NOTE: Some newer thermostat models may draw too much
power from the boiler and will require an additional power
supply to operate properly. Review the instructions provided
with the thermostat to determine if an additional power
supply is needed. Failure to do so could result in improper
boiler and/or thermostat operation.

4. Outdoor Sensor Connections

NOTE: WHEN CONNECTING THE BOILER TO EXTERNAL CONTROLS,
DO NOT RUN 120V CABLES AND CABLES FOR CONTROL CIRCUITS
(WHICH ARE LOW VOLTAGE) TOGETHER. USE SEPARATE CABLES TO
PREVENT INDUCED VOLTAGE ON THE LOW VOLTAGE CIRCUITS.
6 7
Figure 53 - Outdoor Sensor Connection
5. Aquastat (Default) and Tank Sensor (Optional) Connections
(non-Combi Models)
The boiler is designed for managing the production of domestic hot
water via an indirect water heater (IWH) in one of two ways:
i. AQUASTAT (default) - with parameter 228 = 2, the tank temperature
is managed through an ON/OFF aquastat installed in the tank.
When an aquastat is equipped, the boiler target temperature for
DHW IWH demands can be adjusted via parameter 2.10.1 - default
o
setting is 179 F.
ii. TANK SENSOR (optional) - with parameter 228 = 1, the boiler
manages the IWH temperature directly via an NTC sensor installed
in the tank and connected to the boiler (see electrical diagram).
The setting of the tank temperature is done through the "+" and "-"
buttons on the left side of the display.
When a tank sensor is equipped, the boiler target temperature for
DHW IWH demands can be adjusted via parameter 2.10.1 - default
o
setting is 179 F.
Outdoor Sensor
Connector OD on PCB