40
WATER SUPPLIES
This water heater must be installed in accordance with this advice to be covered by the Raypak 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 Raypak water heater 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 warranty does not apply to a copper heat exchanger in a continuous
flow water heater.
Where the saturation index e0.40. 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 Raypak warranty to apply to the pressure relief
valve.
In a scaling water supply calcium carbonate is deposited out of the water onto any hot metallic surface. Where the
saturation index exceeds +0.80, warranty does not apply to a copper heat exchanger in a continuous flow water
heater.
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
on page 40.
CHANGE OF WATER SUPPLY
The changing or alternating from one water supply to another can have a detrimental effect on the operation
and / or life expectation of a water heater cylinder and a temperature pressure relief valve.
Where there is a changeover from one water supply to another, e.g. a rainwater tank supply, bore water supply,
desalinated water supply, public reticulated water supply or water brought in from another supply, then water
chemistry information should be sought from the supplier or it should be tested to ensure the water supply meets
the requirements given in these guidelines for the Raypak warranty to apply.
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SATURATION INDEX (SI)
RAYPAK WATER HEATERS
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
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+0.4
+0.8
0
very corrosive
very scaling
scaling
corrosive
