Water Treatment - DeDietrich 24 Installation And Service Manual

Caution
Please ensure the polarities shown on the terminals are followed, i.e live (L), neutral (N) and earth (
5.2.2

Water treatment

In many cases, it is sufficient to fill the boiler and the heating installation with normal water from the network, without needing to
use any treatment. To avoid possible problems with the boiler and use of the same, check the composition of the water with the
values stated in the tables below.
In accordance with prevailing standards, the water needs to be treated. Water must be treated according to the details of Italian
Presidential Decree 59/09 art.4 par. 14, in compliance with UNI 8065 and the Ministerial Decree of 26 June 2015.
Caution
Do not add any chemical products to the central heating water without first consulting a water treatment specialist.
For example: antifreeze, water softeners, agents to increase or lower the pH, chemical additives and/or inhibitors.
These may cause faults in the boiler and damage the heat exchanger in particular.
Important
Always flush an existing or new CH system thoroughly before a new CH boiler is connected. This step is absolutely
crucial. The flushing helps to remove residue from the installation process (weld slag, fixing products, etc.) and
accumulations of dirt (silt, mud, etc.) The flushing process also encourages heat transfer within the system and
reduces energy consumption. Use a special product to flush the system, if necessary. The product manufacturer
must confirm that the product is suitable for use with all of the materials that are used throughout the central
heating system.
Flush the system section by section. Prevent complications by ensuring that each section has adequate circulation.
Special attention must also be paid to 'blind spots', where there is limited flow and where dirt can accumulate.
When using chemicals to flush the system, the points listed above are even more important. Chemical residue in
the system can have a negative effect. The flushing process must be carried out by a professional and with a great
deal of care. Once the central heating installation has been cleaned and flushed, it can be filled.
Tab.99 Quality of the heating water
Quality
Degree of acidity
Conductivity at 25°C
Chlorides
Iron
Copper
Tab.100 Hardness of the heating water
Hardness
Total hardness of the water in the system until
annual restoration equal to a maximum of 5%
of the installation's capacity
In addition to the quality of the water, the installation also plays a significant role. If materials sensitive to the diffusion of oxygen
are used (such as certain coils for underfloor heating), a high amount of oxygen can penetrate the heating water. This must
always be avoided.
Even when the system is regularly topped up with water from the network, oxygen and other components can still penetrate the
heating water (including limescale). Therefore, uncontrolled topping up must be avoided. Therefore a water meter is required, as
well as a book to record the readings.
Important
Yearly water top ups must not exceed 5% of the capacity of the installation. Never use 100% demineralised or
sterilised water to top up the system without using pH buffering. Doing so will create corrosive water in the central
heating system, which can cause serious damage to various components of the central heating system, including
the heat exchanger. In cascade boilers, the boiler with the lowest permitted water hardness in the table determines
the overall water hardness of the installation.
See also
Periodic check and maintenance procedure, page 197
Dismantling the water-water exchanger, page 202
7804841 - 02 - 20012022
Unit Total output of the installation ≤ 70 kW
pH
μS/cm
mg/litre
mg/litre
mg/litre
Unit Total output of the installation ≤ 70 kW
°F
°dH
mmol/litre
5 Before installation
)
7.0 - 9.0
10 - 500
≤ 50
<0.5
<0.1
5 - 15
2.8 - 8.4
0.5 - 1.5
INIDENS
en
161