ACV WaterMaster 120 Evo, Installation Operation & Maintenance

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A1009341-664Y8300 • B
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 water
flow rate and thermally insulate the exchange surfaces,
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 cir-
cuit. 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 ap-
pliance
Before the system is filled, it must be cleaned in accordance
with standard EN14336. Chemical cleaning agents can be
used.
If the circuit is in bad condition, or the cleaning operation was
not efficient, or the volume of water in the installation is sub-
stantial (e.g. cascade system), it is recommended 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 water
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 corrosion inhib-
itor 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 in-
stalled according to the manufacturer's instructions.
ACV recommends using additives that keep the oxygen
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 in-
structions issued by the manufacturer of the water treat-
ment product.
4. Limit the carbonate concentration in the water
The fill water must be softened if its hardness is higher
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