Viessmann VITOCROSSAL 300 Service Instructions Manual page 31

Water quality requirements
Operating information:
& During expansion or repair work,
only drain the necessary pipework
sections.
& Filters, dirt traps and other blow-
down or separating facilities in the
heating water circuit must be
checked, cleaned and activated
more frequently after the commis-
sioning or new installations, later on
subject to the water treatment
applied (e.g. water softening).
& No further steps are required dur-
ing commissioning, if you fill the
heating system with fully softened
water.
If the heating system is filled, not
with fully softened water, but with
water that meets the requirements
in the above table, also observe
the following during commission-
ing:
& Take the system into use step by
step, starting with the lowest boiler
output and at a high heating water
flow rate. This prevents a localised
concentration of the lime deposits
on the boiler heating surfaces.
(cont.)
& In multi-boiler systems, start all boi-
lers simultaneously to prevent the
entire lime deposit settling in the
heat transfer area of just one boiler.
& Where water treatment is required,
treat even the first fill of the heating
systems prior to commissioning.
This also applies to any subsequent
filling, e.g. when adding top-up
water or after a repair or after sys-
tem expansion.
The formation of lime deposits on the
heating surfaces will be minimised if
these instructions are observed.
Any lime deposits that have formed
because the requirements to VDI
Directive 2035 have not been
observed will in most cases already
have caused a reduction in the ser-
vice life of the installed heating equip-
ment.
Removing the lime deposits is one
option to restore the operational suit-
ability. This measure must be carried
out by a specialist. Inspect the heat-
ing system prior to recommissioning
for possible damage.
It is essential that the faulty operating
parameters are corrected to prevent a
renewed formation of excessive scale
deposits.
Specification
31