74
Filling and venting 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 casing door from escaping
liquids.
1.
Open any non-return valves installed
on site.
2.
Check the pre-charge pressure of the
expansion vessel.
Technical guide
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5600 950 GB
