Viessmann VITOCROSSAL 200 Instructions Manual page 63

Water quality requirements
■ In systems > 50 kW, install a water
meter to record the volume of the fill &
top-up water. Enter the amount of fill
water and the water hardness into the
boiler service check lists.
■ For systems with a specific system vol-
ume in excess of 20 l/kW output (apply
the output of the smallest boiler in
multi-boiler systems), apply the
requirements of the next higher cate-
gory of total output (in accordance with
the table). In case of severe excess (>
50 l/kW), soften the water down to a
total of alkaline earths of ≤
0.02 mol/m 3 .
Operating information:
■ During expansion or repair work, only
drain the necessary 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 commissioning or new installa-
tions, and later on subject to the water
treatment applied (e.g. water soften-
ing).
■ No further steps are required during
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 follow-
ing during commissioning:
(cont.)
■ 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 concentra-
tion of lime deposits on the boiler heat-
ing surfaces.
■ In multi-boiler systems, start all boilers
simultaneously to prevent the entire
lime deposit settling in the heat trans-
fer 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 system expansion.
The build-up 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 Guide-
line 2035 have not been observed will in
most cases already have caused a
reduction in the service life of the instal-
led heating equipment. Removing the
lime deposits is one option to restore the
operational viability.
This measure must be carried out by a
specialist. Inspect the heating system for
possible damage prior to returning it into
use. It is essential that the faulty operat-
ing parameters are corrected to prevent
renewed formation of excessive scale
deposits.
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