Water Supplies - Raypak 910500 Owner's Manual And Installation Instructions

WATER SUPPLIES

This water heater must be installed in accordance with this advice to be covered by the Rheem
warranty.
This water heater is manufactured to suit the water conditions of most public reticulated water supplies.
However, there are some known water supplies which can have detrimental effects on the water heater
and its operation and/or life expectancy. If you are unsure of your water quality, you may be able to
obtain information from your local water supply authority. This water heater should only be connected
to a water supply which complies with these guidelines for the water heater Rheem warranty to apply.
SATURATION INDEX
The saturation index (SI) 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 heat exchanger in a Raypak water heater.
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 pressure relief valve on the Raypak water heater and the temperature pressure relief valve and
cylinder of the storage tank connected to the system. Refer to the Fig 4 on page 26 for the position of
the expansion control valve.
Where the saturation index exceeds +0.80, the Rheem warranty does not apply to a copper heat
exchanger in a Raypak water heater.
Water which is scaling may be treated with a water softening device to reduce the saturation index of
the water.
The following chart details how the Rheem warranty applies according to the saturation index.
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