Technical data

WATER SUPPLIES
10
ANODE INSPECTION AND REPLACEMENT
The anode installed in your storage tank will slowly dissipate whilst protecting the cylinder. The life of the
cylinder may be extended by replacing the anode.
If the anode is not replaced during a five year service (refer to “Major Five Year Service” on page 7) then the
maximum time after installation when the anode should be replaced for this storage tank is 8 years.
For water supplies which are either softened, desalinated or where the water supply may alternate between a
water tank and a reticulated public supply or another supply, it is recommended the anode be replaced within
5 years of installation.
CAUTION
If the water supply has a TDS greater than 150 mg/L and a green anode has not been changed to a black
anode, or if the TDS is greater than 600 mg/L and the anode has not been changed to a blue anode, there is
the possibility the anode may become overactive and hydrogen gas could accumulate in the top of the
storage tank during long periods of no use. In areas where this is likely to occur, the installer should instruct
the householder on how to dissipate the gas safely.
If, under these conditions, the storage tank has not been used for two or more weeks the following procedure
should be carried out before using any electrical appliances (automatic washing machines and dishwashers)
which are connected to the hot water supply.
The hydrogen, which is highly flammable, should be vented safely by opening a hot tap and allowing the
water to flow. There should be no smoking or naked flame near the tap whilst it is turned on. Any hydrogen
gas will be dissipated. This is indicated by an unusual spurting of the water from the tap. Once the water runs
freely, any hydrogen in the system will have been released.
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.
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 storage tank cylinder. 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 10. Refer to the cold water connection detail on page 20 for the
position of the expansion control valve.
-1.0
no warranty applies to a:
temperature pressure relief valve or a
water heater cylinder unless an
expansion control valve is fitted.
SATURATION INDEX (SI)
STORAGE TANKS
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
+0.4 +0.80
very corrosive very scaling
scaling
corrosive