Navien NHB H Series Installation And Operation Manual page 74

System Application #3- Cascade System with DHW Indirect Tank (for High DHW Demand)
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Sub2 Sub1
In this configuration, the full capacity of all boilers will be prioritized to the DHW demand.
Note
●
The aquastat on the DHW indirect tank must be connected to the main unit.
●
Connect the DHW pump to the main unit.
●
Connect the system pump to the units (main or sub).
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System Application #4- Cascade System with DHW Indirect Tank (for High DHW Demand)
●
Sub2 Sub1
Cold water
Backflow preventer
In this configuration, the full capacity of all boilers will be prioritized to the DHW demand.
Note
●
The aquastat on the DHW indirect tank must be connected to the main unit.
●
Connect the DHW pump to the main unit.
●
Connect the system pump to the units (main or sub).
●
74 Installing a Cascade System
Main
Temperature
sensors (required)
Main
Expansion tank
Air separator
Cold water
Backflow preventer
Expansion
tank
12" (30 cm)
maximum
Return
DHW
Cold
water
Temperature
sensors (required)
Dirt collector
Hydro/Air separator
Supply
DHW
Indirect tank
Aquastat
Cold water
Supply
Return
Indirect tank
Aquastat