Filling The Heating Water Buffer Cylinder - Viessmann VITOCELL 140-E Installation And Service Instructions Manual

Commissioning, inspection, maintenance

Filling the heating water buffer cylinder

1. Only fill the heating water buffer cylinder with fill
water of potable quality: See chapter "Fill and top-
up water".
2. Check all connections for leaks. Test pressure:
9.6 bar (0.96 MPa).
If necessary re-seal the connections.
Fill and top-up water
The quality of the fill and top-up water is one of the key
factors for preventing damage caused by deposits or
corrosion in the heating system.
In order to prevent system damage, the European
standards and national guidelines for fill and top-up
water must be observed right from the design stage,
e.g. VDI 2035.
Regular checks of the appearance, water hardness,
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conductivity and pH value of the heating water during
operation lead to higher operational reliability and
system efficiency. These properties must also be
observed for the top-up water. According to
VDI 2035, the quantity and properties of the top-up
water must always be documented in the system log
or maintenance reports.
The basis for filling the heating system is tap water of
■
potable water quality in line with Directive 98/83/EC
and/or (EU) 2020/2184. For use as heating water, it
is normally sufficient to soften the tap water.
VDI 2035 specifies the maximum recommended con-
centrations of alkaline earths (hardeners), depending
on the heating output and the specific system vol-
ume (ratio of the heating output of the heat genera-
tors to the heating water volume of the system): See
the table below.
■ We recommend always softening the fill and top-up
water, as the water hardness can vary due to the
mixture of different sources of supply, and the infor-
mation provided by water supply utilities only gives
average values. The information provided by water
supply utilities is not sufficient for designing the sys-
tem. In addition, it must be taken into account that
the quantity of top-up water that will be added to the
system during its service life cannot be predicted
precisely at the design stage (especially in the case
of existing heating circuits).
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3. Check the function of the shut-off and safety equip-
ment according to the relevant manufacturer's
instructions.
!
Please note
Excessively high operating temperatures
can cause damage to the system.
Adjust the temperature controller and the
high limit safety cut-out so that the heating
water temperature in the heating water buf-
fer cylinder does not exceed 110 °C.
If no aluminium or aluminium alloy components are
■
installed, the heating water in systems with Viess-
mann heat generators does not need to be fully
desalinated.
■ The use of glycol as antifreeze without adequate
inhibition and buffering is not permitted. The suitabil-
ity of an antifreeze or other chemical additive should
be certified by the manufacturer. Chemical additives
in the heating water require more extensive monitor-
ing and maintenance. Observe the manufacturer's
instructions. Viessmann accepts no liability for dam-
age or operational failure arising due to the use of
unsuitable additives, incorrect dosing or poor mainte-
nance.
Chemical water treatments may only be planned and
■
carried out by appropriately qualified specialist com-
panies.