Saturation Index; Maintenance; Minor Six Month Maintenance - Rheem 3805 Series Owner's Manual And Installation Instructions

the water heater 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 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, 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.

Where the saturation index is less than –1.0, the water is very corrosive and warranty does not
apply to the water heater. In a corrosive water supply, the water can attack copper parts and
cause them to fail.

Where the saturation index exceeds +0.40, the water is very scaling and warranty does not apply
to the water heater.

In a scaling water supply the calcium carbonate is deposited out onto any hot metallic surface.
Where the saturation index exceeds +0.4 it is necessary to install an expansion valve between
the non-return valve and the water heater on the cold water line.

Reducing the temperature setting of the water heater can alleviate the scale deposition to the
inner surface of the tank cylinder, and so increase the life expectancy of water heater.

Water which is scaling may be treated with a water softening device to reduce the saturation
index of the water.

Maintenance

Minor six month maintenance

It is recommended minor maintenance be performed every six months by the dwelling occupant.
The minor maintenance includes:

Operate the easing lever on the temperature pressure relief valve. It is very important you raise
and lower the lever gently.
Warning: Exercise care to avoid any splashing of water, as water discharged from the drain line will
be hot. Stand clear of the drain line's point of discharge when operating the valve's lever.

Operate the easing lever on the expansion control valve (if fitted). It is very important you raise
and lower the lever gently.
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