Navien NPE-180A2 Installation Manual page 138

System Diagram for NPE-A2
Outdoor Sensor
Thermostat
System Diagram for NPE-S2
Outdoor Sensor
Thermostat
For details, refer to the installation manual that is provided with the H2Air add-on controller kit.
138 Appendixes
NPE-A2 Series
Water Heater
Heat Demand
Output
Space Heating
Supply
Space Heating
Return
Mixing Valve
DHW Supply
NPE-S2 Series
Water Heater
Heat Demand
Output
Space Heating
Supply
Space Heating
Return
Mixing Valve
DHW Supply
Internal Pump
Expansion
Tank
Check
Valve
Flow Switch
External Pump
(Optional)*
*Connect the external pump cable
to the NPE-A2 PCB.
Expansion
Tank
Check
Valve
Flow Switch
External Pump*
*Connect the external pump cable
to the NPE-S2 PCB.
Cold Water
Supply
Cold Water
Supply