Noritz GHQ-C2801WX-FF US, Installation Manual, Page: 42 / 84

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The illustration is an example. Check with the actual Combi Boiler about the position of piping, and form.
8.2 Water Treatment
If this Combi Boiler will be installed in a location where the hardness of the supply water is high, scale Build-up
may cause damage to the Plate Heat Exchanger.
Perform suggested treatment and maintenance measures to be taken based on the water hardness level
according to the below table.
Type of Water Hardness Level Treatment Device*
1
Flush Frequency*
2
Soft
0-1 gpg
(0-17 mg/L)
None None
Slightly Hard
1-3 gpg
(17-51 mg/L)
Moderately Hard
3-7 gpg
(51-120 mg/L)
Scale Shield or
Water Softener
Once a Year*
3
Hard
7-10 gpg
(120-171 mg/L)
Very Hard
10-12 gpg
(171-200 mg/L)
Extremely Hard
> 12 gpg
(> 200 mg/L)
Treatment Guidelines
* 1 When selecting a treatment device,
you must consult with the device’s
spec sheet and installation manual for
guidelines and limitations.
Not all water supplies are compatible.
A water test may be required.
* 2 Install Isolation Valve to allow for
flushing.
* 3 Flushing is required if a water
treatment device is not installed.
NOTE Damage to the Combi Boiler as a result of the items below is not covered by the Noritz America
Limited Warranty.
• Water in excess of 12 gpg (200 mg/L) of hardness
• Poor water quality (See the Water Quality List on page 14).
Water treatment device
• The water must be treated with either the a Noritz Scale Shield or a water softener.
• Water softeners may be regulated by the local water jurisdiction, consult with the manufacturer for code,
sizing, and installation guidelines.
The below diagram is for reference only. For more information about Scale Shield, contact Noritz America at
http://support.noritz.com/ or 1-866-766-7489.
Water Treatment System
City Water Supply
Pressure Relief Valve
Hot Water to
Fixtures
Shutoff Valve
Shutoff Valve
Drain
Sediment Filter
Water Treatment Device
Shutoff Valve
To Auto Feeder
To DHW Cold
Water Supply
Cold supply to Combi Boiler
Backflow Preventer
DHW Outlet
Cold Inlet
Pressure Reducing Valve
Connecting the DHW pipe