ACV E-Tech W 09 Mono, Installation Operation & Maintenance

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A1007841-664Y7800 • A
RECOMMENDATIONS FOR THE PREVENTION OF CORROSION AND SCALING IN
HEATING SYSTEMS
How oxygen and carbonates can affect the
heating system
Oxygen and dissolved gasses in the water of the prima-
ry circuit contribute to the oxidation and the corrosion of
the system components that are made of ordinary steel
(radiators, ...). The resulting sludge is then deposited in
the appliance exchanger.
The combination of carbonates and carbon dioxide
in the water results in the formation of scale on the
hot surfaces of the installation, including those of the
appliance exchanger.
These deposits in the heat exchanger reduce the wa-
ter flow rate and thermally insulate the exchange sur-
faces, which is likely to damage them.
Sources of oxygen and carbonates in the
heating circuit
The primary circuit is a closed circuit; the water it
contains is therefore isolated from the mains water.
When maintaining the system or filling up the circuit,
water renewal results in the addition of oxygen and
carbonates in the primary circuit. The larger the water
volume in the system, the larger the addition.
Hydraulic components without an oxygen barrier (PE
pipes and connections) admit oxygen into the system.
Prevention Principles
1. Clean the existing system before installing a new
appliance
Before the system is filled, it must be cleaned in ac-
cordance with standard EN14336. Chemical cleaning
agents can be used.
If the circuit is in bad condition, or the cleaning oper-
ation was not efficient, or the volume of water in the
installation is substantial (e.g. cascade system), it is rec-
ommended to separate the appliance from the heating
circuit using a plate-to-plate exchanger or equivalent. In
that case, it is recommended to install a hydrocyclone
or magnetic filter on the installation side.
2. Limit the fill frequency
Limit fill operations. In order to check the quantity of wa-
ter that has been added into the system, a water meter
can be installed on the filling line of the primary circuit.
Automatic filling systems are not recommended unless
the fill frequency is monitored and the scale and corro-
sion inhibitor remain at the correct levels.
If your installation requires frequent water refilling,
make sure your system is free of water leaks.
Inhibitors may be used in accordance with standard
EN 14868.
3. Limit the presence of oxygen and sludge in the
water
A deaerator (on the appliance flow line) combined
with a dirt separator (upstream of the appliance) must
be installed according to the manufacturer's instruc-
tions.
ACV recommends using additives that keep the ox-
ygen in solution in the water, such as Fernox (www.
fernox.com) and Sentinel (www.sentinel-solutions.
net) products.
The additives must be used in accordance with the
instructions issued by the manufacturer of the water
treatment product.
4. Limit the carbonate concentration in the water
The fill water must be softened if its hardness is high-
er than 20° fH (11,2° dH).
Check regularly the water hardness and enter the
values in the service log.
Water hardness table :
5. Control the water parameters
In addition to the oxygen and the water hardness,
other parameters of the water must be checked.
Treat the water if the measured values are outside
the range.
Water hardness °fH °dH mmolCa(HCO3)2 / l
Very soft 0 - 7 0 - 3.9 0 - 0.7
Soft 7 - 15 3.9 - 8.4 0.7 - 1.5
Fairly hard 15 - 25 8.4 - 14 1.5 - 2.5
Hard 25 - 42 14 - 23.5 2.5 - 4.2
Very hard > 42 > 23.5 > 4.2
Acidity 6,6 < pH < 8,5
Conductivity < 400 μS/cm (at 25°C)
Chlorides < 125 mg/l
Iron < 0,5 mg/l
Copper < 0,1 mg/l
EN
Technical Specifications