Rheem Premier Hiline Owner's Manual And Installation Instructions page 14

WATER SUPPLIES
SATURATION INDEX
The saturation index is used as a measure of the water‟s corrosive or scaling properties.
In a corrosive water supply, the water can attack copper parts and cause them to fail. Where the saturation
index is less than –1.0, the water is very corrosive and the Rheem warranty does not apply to a copper
sheathed heating unit. A corrosion resistant heating unit must be used for the Rheem warranty to apply to
the heating unit. This water heater is supplied fitted with a corrosion resistant heating unit.
In a scaling water supply calcium carbonate is deposited out of the water onto any hot metallic surface.
Where the saturation index exceeds +0.40, the water is very scaling. An expansion control valve must be
fitted on the cold water line after the non-return valve to protect and for the Rheem warranty to apply to the
temperature pressure relief valve and water heater cylinder.
Where the saturation index exceeds +0.80, the Rheem warranty does not apply to a standard watts density
heating unit. A low watts density heating unit must be used for the Rheem warranty to apply to the heating
unit.
Water which is scaling may be treated with a water softening device to reduce the saturation index of the
water.
Refer to the Saturation Index chart
position of the expansion control valve.
Contact Rheem Service or their nearest Accredited Service Agent if a replacement heating unit is required.
very corrosive
SUMMARY OF WATER CHEMISTRY ADVICE AFFECTING WARRANTY
The water heater and its components are not suitable for certain water chemistries. Those chemistries are
listed below. If the water heater is connected at any time to a water supply with the following water chemistry,
the Rheem warranty will not cover any resultant faults on the components listed below:
Water Chemistry
Chloride > 250 mg/L
pH < 6.0
Saturation Index (SI) < -1.0
Saturation Index (SI) > +0.4
(if an expansion control valve is not fitted)
Saturation Index (SI) > +0.8
on page 14. Refer to the
SATURATION INDEX (SI)
SOLAR WATER HEATERS - ELECTRIC BOOST
WITHIN WARRANTY
SPECIFICATION
-1.0
SATURATION INDEX
(calculated @ 80°C water temperature)
corrosive
cold water connection detail on page
0 +0.4
scaling
very scaling
Component
water heater cylinder and heat exchanger
water heater cylinder and heat exchanger
copper sheathed heating unit
water heater cylinder and heat exchanger
temperature pressure relief valve
standard watts density heating unit
14
37 for the
+0.8