Navien NFC-250/175H Installation Manual page 36

Configuring a Zone System
The NFC-H boiler can control up to 3 zones utilizing
zone valves or zone pumps. After installing the
system, the boiler operation must be configured
accordingly using the front panel.
To configure a zone system:
On the front panel, press the Menu button (
enter the setting menu, and then select 2. Space Htg
Operation > 2. Zone Settings.
3.6.1 Temperature Control Device
Applications
NFC-H series boilers come with water adjustment
valves and mixing valves included as to ensure a
stable supply of hot water without requirements for
additional direct water pressure control valves (flow
restrictors) or mechanical mixing valves.
When setting up the system, do not install water
●
pressure control valves or flow restrictors on the
direct water supply lines.
When setting up the system, do not install
●
additional mechanical mixing valves on the DHW
supply line.
Water Adjustment Valve
The adjustment valve works in conjunction with the
flow sensor to detect and control the direct water
flow within the system, and is installed on the water
piping module. Refer to "1.4 Components" on page
11 for details.
Mixing Valve
The mixing valve controls the amount of cold water
that is mixed with the hot water in order to provide
a stable supply of DHW. It is installed on the water
pipe module. Refer to "1.4 Components" on page
11 for details.
36 Installing the System Piping
3.6.2 Examples of System Applications
Refer to the following examples to properly
implement a system for space heating, DHW
supply, or both. These examples are provided to
suggest basic guidelines when you install the boiler
system. However, the actual installation may vary
depending on the circumstances, local building
codes, or state regulations. Check the local building
codes and state regulations thoroughly before
) to
installation, and comply with them fully.
WARNING
Ensure the power is turned off while making
wiring connections. Boiler components or
the boiler may fail and result in serious injury
or death if power is supplied during wire
connection. Product failures caused by incorrect
installation are not covered by warranty.