Navien NHB Series, Installation & Operation Manual

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30 Installing the System Piping
3.3.1 Make-up Water Connection
An external make-up water connection is required. The illustration
below shows an example of an external water supply connected to
the system piping.
Pressure Reducing Valve
Backflow Preventer
Air Separator
Pump
Expansion Tank
To System
Make-up Water
From
System
3.4 Testing the Water System
WARNING
Ensure that the boiler is full of water before firing the burner.
Operating the unit without completely filling it will damage
the boiler. Such damage is not covered by the warranty, and
may result in property damage, severe personal injury, or
death.
Perform a leak test after installing the boiler’s water system to
make sure that the system has been installed properly. Follow the
instructions below to perform a leak test on the water system.
1. Fill the system only after ensuring that the water chemistry
meets the requirements.
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 205 mg/l
Total Dissolved Solids (TDS) Up to 500 mg/l
Zinc Up to 5 mg/l
Chlorine Up to 4 mg/l
Note
Proper maintenance of the boiler is required when
water quality does not meet standards. Damage caused
by poor water quality is not covered under warranty.
The table above shows the maximum contaminant
levels allowed. If you suspect that your water is
contaminated in any way, discontinue the use of water
heater and contact an authorized technician or licensed
professional.