Rheem GAS DOMESTIC OUTDOOR WATER HEATER - Manual (Page 30)

30
WATER SUPPLIES
Your water heater is manufactured to suit the water conditions of most Australian
metropolitan 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 can obtain information from
your local water supply authority.
ANODE
In areas where the total dissolved solids (TDS) exceeds 600 mg/L it is possible the
black anode, which is the standard anode fitted to the water heater, may be
excessively active. To alleviate this, the black anode should be replaced with one
colour coded blue. Where the TDS of the water is less than 40 mg/L, such as when
the water has been deionised or is from an alpine supply, a high potential anode,
colour coded green, should be used. The changing of anodes must be carried out
by a plumber or authorised service person.
CAUTION
If your water supply has a TDS greater than 600 mg/L and the anode has not been
changed to a blue one, there is the possibility hydrogen gas could accumulate in the
top of the water heater during long periods of no use.
If, under these conditions, the water heater 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 again,
any hydrogen in the system will have been released. In areas where this is likely to
occur, the householder should be instructed by the installer on how to dissipate the
gas safely.
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. In a scaling water supply calcium carbonate is deposited out of the
water onto any hot metallic surface. Where the saturation index is greater than
+0.40, the water is scaling and an expansion control valve* must be fitted on the
cold water line after the non-return valve.
* Refer to the
cold water connection detail on page 22.
WATER HEATERS NOT INSTALLED IN ACCORDANCE WITH THE ABOVE
ADVICE WILL NOT BE COVERED BY THE WARRANTY.