Technical Information For Water Treatment - Wolf CGB-75 Installation And Operating Instructions Manual

The system must be thoroughly cleaned / flushed before
commissioning and a sludge filter/dirt trap (<5 μm) e.g. Wolf
accessory installed in the return line. This must be in close
proximity to the boiler.
The fill and top-up water must only be treated with a desalina-
tion process. The "Water treatment diagram" and the "Maxi-
mum permissible total hardness" table shows the degree to
which water treatment is required. The system water must not
fall below a total hardness of 2°dH, which corresponds to con-
ductivity of ≈ 60 μS/cm. The max. permissible total hardness
and the corresponding max. conductivity are system-specific
and must be calculated (see also "Maximum permissible
total hardness" table). The desalinated water (conductivity
<=30 μS/cm) must not be mixed with untreated DHW. The
addition of chemicals or de-scaling using single stage ion
exchangers is not permissible, as system damage with asso-
ciated water leaks may occur.
We recommend regular emptying of the sludge filter and
keeping of a system log.
Permissible methods:
- Desalination using mixed-bed cartridges. These are multi
stage ion exchangers. We recommend, for example, using
e.g. Grünbeck or Judo cartridges for the first fill, and later
as and when required.
- Desalination via reverse osmosis
- Topping up with distilled water
Heating water quality requirement relating to the entire heating system
Total hardness/
total alkaline earths
[kW] [°dH]
1 ≤ 50 ≤ 16.8
2 50-200 ≤ 11.2
3 200-600 ≤ 8.4
4 ≤ 600 ≤ 0.11
3)
The total amount of fill and top-up water over the life cycle of the boiler must not exceed three times the nominal volume of the
heating system.
In systems with multiple boilers, the max. rated heating output of the smallest boiler must be used in accordance with VDI 2035
1)
High salinity < 800 µS/cm
2)
Low salinity < 100 µS/cm
< 0.11°dH recommended standard; permissible up to limit of < 1°dH
3)
Table 1
Gradual increase in the demand for the specific System volume (V
ing output.
The total amount of fill water over the life cycle of the appliance must not exceed three times the nominal volume of the heating
system.
Please note: The total hardness must not fall below 2°dH.
3062555_201804
26. Technical information for water treatment
Limits in relation to the specific system volume VA
(VA = System volume / maximum rated heating power
Total hardness conversion: 1 mol/m³ = 5.6 °dH = 10°fH
V ≤ 20 l/kW
A
Conductivity
2)
at 25°C
[mol/m³] C [µS/cm]
≤ 3.0 < 800
≤ 2
≤ 1.5 < 100
≤ 0.02
18
14
10
6
No water treatment
required
2
200
Figure: Water treatment
Treatment of heating water in accordance with VDI 2035:
We recommend a heating water pH value of between 8.2 and
8.5, also in mixed installations with various materials.
Request a water analysis from the water supply utility. This
must verify that the total hardness is sufficiently low.
For a specific system volume V
smaller limit must be used, for V
but-one limit and for V
from the following table must be used.
For a specific system volume of >50 l/kW, adjust the total hard-
ness to 2-3°dH using a desalination process. This corresponds
to conductivity of 60 - 100 μS/cm.
If the boiler is integrated in the system without a low loss
header, adjust the total hardness to 2 - 3°dH (Conductivity =
60 - 100 μS/cm).
V > 20 l/kW and < 50 l/kW
A
Total hardness/ Conductivity
total alkaline earths at 25°C
[°dH] [mol/m³] C [µS/cm]
≤ 11.2 ≤ 2
≤ 8.4 ≤ 1.5
≤ 0.11 ≤ 0.02
3)
≤ 0.11 ≤ 0.02
3)
= system volume / lowest individual output) and total heat-
S
Water treatment
required
600 800 1000 1200
400
System volume in l
>= 10l/kW the next
A,specific
>= 20l/kW the next-
A,specific
>= 40l/kW the smallest value
A,specific
)
1)
V ≥ 50 l/kW
A
Total hardness/
2)
total alkaline earths
[°dH] [mol/m³]
< 800 ≤ 0.11 ≤ 0.02
3)
≤ 0.11 ≤ 0.02
3)
< 100 ≤ 0.11 ≤ 0.02
3)
≤ 0.11 ≤ 0.02
3)
CGB-75
CGB-100
1400 1600 1800 2000
Conductivity
2)
at 25°C
C [µS/cm]
< 800
< 100
43