82 Installing a Cascade System
When installing a cascade system, carefully consider the design of the system and the features of the installation
location. Follow all local codes and regulations, as well as all guidelines for installing the combi-boiler and water
heaters. The following sections describe additional considerations that are specific to installing cascade systems.
Read them carefully before designing or installing the system.
8.1 Connecting Water Supplies
Several options are available for applying a cascade system of combi-boilers and water heaters. The options
shown here are only examples. The setup you choose will vary based on the installation location, local building
codes, and other factors. Follow all applicable regulations when installing a cascade system.
You can connect up to 1 combi-boiler and 15 Navien water heaters (NPE-A2 or NPE-S2 model) to meet high-
volume heating demands. Some possible connection options include the following:
Example of a Basic Cascade System Application
Pressure
Relief Valve
Main
Faucet
Ball Valve
Optional System
Temperature Sensor
NaviClean
Ball Valve
<NPE-A2 Series>
<NPE-A2 Series>
Check Valve
Air Separator
with Expansion
Tank
Pump
Heating
Supply
Heating Return
Sub2
Sub1
[NFC-H]
Note
●
System application drawings are intended to explain the system piping concept only.
●
Install a NaviClean Filter in the system heating return to remove foreign objects from the system.
Foreign objects inside the system may result in abnormal system operation.
●
Refer to “3.4 Filling the System” on page 32 for make-up water connections and refer to the
requirements of your local codes to ensure compliance.
●
Use pumps with integral check valves or install check valves at the pump outlets.
●
Adjust the settings at the main unit as the cascade system uses only the main unit settings.
Changes made to the sub units are ignored.
●
Each unit must be configured for cascade operation.
8. Installing a Cascade System
Summary of Contents for NFC-250/175H
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