24 Installing the System Piping
WARNING
Installing the pressure relief valve improperly
may result in property damage, personal injury,
or death. Follow all instructions and guidelines
when installing the pressure relief valve. The
valve should be installed only by a licensed
professional.
The DHW pressure relief valve is not supplied,
but is required.
The following examples are pressure relief valves
approved for use
with the boiler:
●
Wilkins P-1000A (Zurn Industries)
●
Conbraco 17-402-04
●
Watts Industries 3L (M7)
●
Cash Acme FWL-2,
3
/
4
in
Pressure
Relief
Valve
CAUTION
Install the pressure relief valve as close to the
boiler as possible. No other valve should be
installed between the pressure relief valve and
boiler.
Contaminant
Maximum Allowable Level
Total Hardness Up to 200 mg/l
(12 grains/gallon)
Aluminum
0.05 to 0.2 mg/l
Chloride
Up to 250 mg/l
Copper
Up to 1.0 mg/l
Iron
Up to 0.3 mg/l
Manganese
Up to 0.05 mg/l
pH
6.5 to 8.5
Sulfate
Up to 250 mg/l
Total Dissolved
Solids (TDS)
Up to 500 mg/l
Zinc
Up to 5 mg/l
Navien is not responsible for performance issues of
the domestic system by scaling or accumulation of
dirt; suitable steps shall be taken by the installer and
user to avoid water quality related issues.
Freeze Protection
Navien recommends heat tracing and insulating the
DHW water pipes. Pipe enclosures may be packed
with insulation for added freeze protection. Freeze
damage is not covered by the warranty.
3.2.2 Essential Elements in a DHW
System
DHW Heat Exchanger
The DHW heat exchanger is installed inside the
Navien NCB-H boiler.
Drain and Isolation Valves
Install drain and isolation service valves on the inlet
and outlet of the DHW heat exchanger, so it can be
flushed free of possible build-up caused by dirt or
hard water. The optional Navien Plumb-Easy Kit is
recommended.
Pressure Relief Valve for DHW
To complete the installation of the DHW system,
you must install an approved
3
/
4
in, maximum 150
psi pressure relief valve on the domestic hot. The
Navien NCB-H boiler has a built-in high temperature
shut off switch, so install a “pressure only“ relief
valve.
Summary of Contents for NCB-190/060H
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