Navien NHB H Series Installation And Operation Manual page 75

System Application #5- Cascade System with DHW Indirect Tank (for Low DHW Demand)
●
DHW
Indirect
tank
Aquastat
Cold water
In this configuration, space heating and DHW can operate simultaneously.
Note
●
The aquastat on the DHW indirect tank must be connected to a sub unit.
●
If a dedicated sub unit is used, the input capacity requirement of the indirect tank shall not exceed
●
the capacity of the single boiler.
Connect the DHW pump to the sub unit.
●
Connect zone pumps to the zone controller. Do not connect zone pumps to the main or sub units.
●
System Application 6 - Cascade System with DHW Indirect Tank (for Low DHW Demand)
●
DHW
Indirect
tank
Aquastat
Cold water
Cold water
In this configuration, space heating and DHW can operate simultaneously.
Note
●
The aquastat on the DHW indirect tank must be connected to a sub unit.
●
If a dedicated sub unit is used, the input capacity requirement of the indirect tank shall not exceed
●
the capacity of the single boiler.
Connect the DHW pump to the sub unit.
●
Connect zone pumps to the zone controller. Do not connect zone pumps to the main or sub units.
●
Sub2 Sub1
Sub2 Sub1
Backflow preventer
Main
Temperature
sensors (required)
Main
Expansion tank
Supply
Air separator
Cold water
Backflow
preventer
Expansion tank
12" (30 cm)
maximum
Return
Supply
Return
Temperature
sensors (required)
Dirt collector
Hydro/Air separator
Installing a Cascade System 75