Viessmann Vitocrossal 200 Service Instructions For Contractors page 75

Water quality requirements
Note
Adherence to the following requirements
is a warranty condition.
Prevention of damage due to scaling
Prevent excessive scale build-up (calcium carbonate) on the heating surfaces. For
heating systems with operating temperatures up to 100 °C, the directive VDI 2035-1
"Prevention of heating system damage – scaling in DHW and hot water heating sys-
tems" applies [in Germany] together with the following standard values (see also the
relevant explanations in the original directive).
Total heating output
kW
> 50 to ≤ 200
> 200 to ≤ 600
> 600
The standard values assume the follow-
ing:
■ The total volume of fill and top-up
water during the service life of the sys-
tem will not exceed three times the
water content of the heating system.
■ The specific system volume is less
than 20 l/kW heating output. In multi
boiler systems, apply the output of the
smallest boiler.
■ All measures to prevent corrosion on
the water side in accordance with
VDI 2035-2 have been implemented.
The manufacturer's warranty excludes
damage due to corrosion and scaling.
Total alkaline earths
mol/m 3
≤ 2.0
≤ 1.5
< 0.02
Soften the fill and top-up water in heating
systems operating under the following
conditions:
■ The total of alkaline earths in the fill
and top-up water exceeds the stand-
ard value.
■ Higher fill and top-up water volumes
are expected.
■ The specific system volume is higher
than 20 l/kW heating output. In multi
boiler systems, apply the output of the
smallest boiler.
Total hardness
°dH
≤ 11.2
≤ 8.4
< 0.11
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