70
Note
Work on the refrigerant circuit may only
by carried out by certified personnel
(according to EC Directives 842/2006
and 303/2008).
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).
A
1.
Open any non-return valves installed
on site.
2.
Check the pre-charge pressure of the
expansion vessel and adjust if
required (see page 72).
3.
Fill (flush) and vent the secondary cir-
cuit via an on-site connection.
4.
Check the system pressure at pres-
sure gauge
A
and top up with water
if required.
Minimum system pressure: 0.8 bar
Permiss. operating pressure: 3.0 bar
5.
Place the control panel in its service
position; see page 85.
6.
Open programming unit; see
page 83.
7.
Remove separating plate; see
page 86.
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5601 429 GB
