68
■ In systems > 50 kW, install a water
meter to capture 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 require-
ments of the next highest category of
total output (in accordance with the
table). In the 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 pipework sec-
tions.
■ 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 recommission-
ing, and later on as required, subject
to the water treatment applied (e.g.
water softening).
■
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
:
■ Commission the system step by step,
starting with the lowest boiler output
and at a high heating water flow rate.
This prevents a localised concentra-
tion of limescale deposits on the boiler
heating 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, after a
repair or after system expansion.
The build-up of limescale deposits on the
heating surfaces will be minimised if
these instructions are observed.
Any scale deposits that have formed
because the requirements to VDI Direc-
tive 2035 have not been observed, will in
most cases already have caused a
reduction in the service life of the instal-
led heating appliance. Removing the
limescale deposits is one option for
restoring 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.
Water quality requirements
Water quality requirements
(cont.)
5692 908 GB
