Navien NCB-20LHWE Installation & Operation Manual page 23

Before connecting the condensate drain, choose one of the
following disposal options:
a
b
a. From the boiler directly into an external drain.
b. From the boiler, through a neutralizing agent, and then
into an external drain.
If you choose this option, the neutralizing agent
Note
must be replaced periodically. Depletion of
the neutralising agent will vary, based on the
operation, the neutralizer should be checked
every few months for depletion and replaced as
needed.
c. From the boiler into a laundry tub.
The bottom of the boiler must be higher than
Note
the top of the laundry tub to use this option. The
condensate line must have a negative slope to
drain properly.
d. From the boiler into a condensate pump, and then into a
laundry tub.
A pump can be used when there is a long
Note
distance between the boiler and the laundry tub
or when the bottom of the boiler is lower than the
top of the laundry tub.
c
d
To connect the condensate drain:
1. Connect a drain line to the condensate trap.
The condensate trap outlet will allow 21.5mm.
Use only corrosion-resistant material for the drain line,
such as PVC or CPVC. Do not reduce the size of the drain
line to less than 21.5mm.
The drain line can be connected to the condensate trap
using a condensate trap hose. The hose connection
must be secured with a hose clip.
Note
This hose is supplied along with the boiler.
2. Place the free end of the drain line into an appropriate drain.
3. If you are using a condensate pump, ensure that the pump
allows for up to 3.78 LPH of drainage for each boiler in the
system.
4. If you are not using a condensate pump, ensure that the
drain line is pitched downward at a minimum slope of 6 mm
per 30 cm.
Water must be poured into the exhaust connection to
Note
ondensate trap.
Installing the System Piping 23