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Definition of water types
Drinking water
- Tap water, in conformity with the
European Drinking Water Directive:
98/83/EC, dated 3 November 1998.
Softened water
- Water, from which calcium and
magnesium ions have been partially
removed.
Demineralized water
- Water, from which almost all salts
have been removed (very low
conductivity).
Distilled water
- Water, in which no more salts are
present.
Installation
Water and hydraulic system
DHW quality
Expansion vessel
The CH-installation has to be fitted with
an expansion vessel. The expansion
vessel used has to comply with the
water contents of the installation.
It is not necessary to install an
expansion vessel to each boiler. One
single, central installed expansion
vessel is sufficient. When using a
single expansion vessel the handles of
the valves on the flow and return pipes
below the boiler have to be removed
whilst open.
A boiler expansion vessel can be
connected on the cross union inside
the return pipe to each boiler, if
required. The connection is fitted with
a 3/4" male thread blanking cap.
Expansion DHW cylinder circuit
When applying a DHW cylinder
connected directly to the boiler
(ATAG cylinder connection with use
of diverter valve) the circuit between
the diverter valve and the DHW
cylinder should be provided of an
expansion tank. See also page 34.
For installation in UK, please refer to
UK standards.
Expansion vessel
