Weishaupt WTC 45-A, Installation And Operating Instructions Manual, Page: 13 / 90

13
3
0
5
0
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25
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15
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Max. total hardness of heating water for WTC 45-A
Fill and top up water quantity [ l ]
To
ta
l har
dness [°dH]
3.5 Demands on the heating water
3.5.1 Permissible water hardness
Note: In accordance with VDI-Guideline 2035
the following demands must be met by the
heating water.
• The untreated fill and top up water must be of
domestic water quality (colourless, clear, without
scaling),
• the fill and top up water must be pre-filtered
(mesh width max. 25 µm),
• the pH value must be 8.5 ± 0.5,
• avoid oxygenation of the heating water
(max. 0.05 mg/l),
• if any system components are not diffusion resistant
the unit should be separated from the heating circuit
using a system separator.
The permissible water hardness is determined relative to
the fill and top up water quantity.
☞
Determine if measures for water treatment are
necessary using the diagram.
If the fill and top up water lies in the range of the upper
limit curve:
☞
Treat fill and top up water.
If the fill and top up water lies in the range of the lower
limit curve, the water does not need to be treated.
Note: Document fill and top up water quantity in the
system log book.
0
5
0
10
20
25
30
15
500 1000 1500 2000 2500 3000 3000 3500
Max. total hardness of heating water for WTC 60-A
Fill and top up water quantity [ l ]
To
ta
l har
dness [°dH]