Version 1.4
20 NCB-E Service Manual
4.1 Setting the DIP Switches
CAUTION
Do not remove the front cover unless the power to the
boiler is turned off or disconnected.
Failure to do so may
result in electric shock.
The boiler has two DIP switch locations: on the main circuit board
(PCB) and on the front panel. Each location has two sets of DIP
switches that control the functionality of the boiler. Set the DIP
switches appropriately, based on the installation environment and
the gas type.
4.1.1 Setting the DIP Switches
Circuit Board DIP Switches
1 2 3 4 5 6
ON
1
2 3 4 5 6
7
8
ON
●
Set of DIP Switches 1 (Set of 6)
The DIP switches 1 on the circuit board configure the boiler’s
model and gas type settings. These configurations are set at the
factory and should not be changed. The following tables describe
the functions of the DIP switches and their settings.
Ex) DIP Switch On/Off
Switch
Function
Setting
1 & 2
Operation
Status
Normal
1-OFF, 2-OFF
Forced Max (2 stage) 1-ON, 2-OFF
Forced Min (1 stage)
1-OFF, 2-ON
1 Stage Max
1-ON, 2-ON
3
Reserved
-
-
4
Reserved
-
-
5 & 6
Capacity
select
NCB-150E
5-ON, 6-ON
NCB-180E
5-OFF, 6-OFF
NCB-210E
5-ON, 6-OFF
NCB-240E
5-OFF, 6-ON
●
Set of DIP Switches 2 (Set of 8)
The DIP SW 2 on the circuit board configures additional features at
the time of installation, such as temperature control modes.
Switch
Function
Setting
1
Temperature
Control
Return Water
1-ON
Supply Water
1-OFF
7
Thermostat
or Zone
Controller
Unused (Permanent
space heating
demand)
7-ON
Used
7-OFF
8
Exhaust
Thermostat
Temperature Limit
Unused (CPVC)
8-ON
Setting (PVC)
8-OFF
NOTE
●
When PCB DIP switch #8 on DIP switches 2(set of 8), the
boiler does not operate without an exhaust thermostat
installed.
●
When you set PCB switch #8 on DIP switches 2(set of 8) to on,
ensure that CPVC piping is used for exhaust venting.
4. System Details
