Viessmann BWT 241.A Series, Installation And Service Instructions Manual

Page: 55 / 124

55
Note
The system must be protected
against frost down to –15 °C.
Viessmann heat transfer medium is a
ready-mixed ethylene glycol-based
medium, for down to –15 °C, contain-
ing inhibitors for corrosion protec-
tion.
3. Check the connections for possible
leaks. Replace faulty or displaced
gaskets.
Information on setting the primary
pump
Temperature differential between the
primary flow and primary return:
3 K to 5 K.
For this, it may be appropriate to set the
primary pump to a lower stage.
Filling and venting on the secondary side
Unsuitable fill and top-up water increa-
ses the level of deposits and corrosion
and may lead to system damage.
Regarding the quality and amount of
heating water, incl. fill and top-up water,
observe the VDI 2035 [or local regula-
tions].
■ Thoroughly flush the entire heating
system prior to filling it with water.
■ Only use fill water of potable quality.
■ Soften fill water with a hardness above
16.8 °dH (3.0 mol/m
3
), e.g. with the
small softening system for heating
water (see the Viessmann Vitoset
pricelist).
!
Please note
To prevent equipment damage,
protect electrical components on
the shield from escaping liquids.
1. Open any on-site non-return valves if
installed.
2. Check the pre-charge pressure of the
expansion vessel (see page 57).
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5601 598 GB
Service