28
See page 11.
Filling the heating system
Fill water
According to EN 1717 with DIN 1988-100, as a heat
transfer medium for DHW heating, the heating water
must meet fluid category ≤ 3. This requirement is met if
water of potable quality is used as heating water. For
example, if additives are used, the additive manufac-
turer must specify which category the treated heating
water comes under.
!
Please note
Unsuitable fill water increases the level of
deposits and corrosion and may lead to appli-
ance damage.
■
Flush the heating system thoroughly before
filling.
■
Only use fill water of potable water quality.
■
Special antifreeze suitable for heating systems
can be added to the fill water. The antifreeze
manufacturer must verify its suitability.
■
Fill and top-up water with a water hardness in
excess of the following values must be soft-
ened, e.g. with a small softening system for
heating water.
Total permissible hardness of the fill and top-up water
Total heating output
Specific system volume
kW
< 20 l/kW
≥
20 l/kW to < 50 l/kW
≥
50 l/kW
≤
50
≤
3.0 mol/m
3
(16.8 °dH)
≤
2.0 mol/m
3
(11.2 °dH)
< 0.02 mol/m
3
(0.11 °dH)
>
50 to
≤
200
≤
2.0 mol/m
3
(11.2 °dH)
≤
1.5 mol/m
3
(8.4 °dH)
< 0.02 mol/m
3
(0.11 °dH)
>
200 to
≤
600
≤
1.5 mol/m
3
(8.4 °dH)
≤
0.02 mol/m
3
(0.11 °dH)
< 0.02 mol/m
3
(0.11 °dH)
>
600
< 0.02 mol/m
3
(0.11 °dH)
< 0.02 mol/m
3
(0.11 °dH)
< 0.02 mol/m
3
(0.11 °dH)
A
B
Fig. 20
Shown with connection set for finished walls
(accessories)
1.
Check the pre-charge pressure of the diaphragm
expansion vessel (see page 47).
2.
Close the gas shut-off valve.
3.
Open shut-off valves
B
on the heating water side.
4.
Fill the heating system via boiler drain & fill valve
A
in the heating return (depending on the connec-
tion set either on the side or above the boiler). Min-
imum system pressure
>
1.0 bar (0.1 MPa).
Note
If the control unit was not switched on prior to filling
the system, then the servomotor of the diverter
valve will still be in its central position and the sys-
tem will be completely filled.
Commissioning, inspection, maintenance
Removing the front panels
5778741
