Ariston Type C Installation, Servicing And Operating Instructions page 15

10. Installation requirements
Electrical Supply
All electrical work carried out must be in accordance with all
current local Building Regulations and British Standards.
The appliance requires an earthed 230V - 50 Hz supply and
must be in accordance with current I.E.E. It must also be
possible to be able to completely isolate the appliance
electrically. Connection should be via a 3 amp fused double-
pole isolating switch with contact separation of at least 3 mm
on both poles. Alternatively, a fused 3 Amp. 3 pin plug and
unswitched socket may be used, provided it is not used in a
room containing a bath or shower. It should only supply the
appliance.
The boiler is suitable for sealed systems only. The maximum
working pressure for the appliance is 6 bar. All fittings and
pipework connected to the appliance should be of the same
standard. If there is a possibility of the incoming mains
pressure exceeding 6 bar, particularly at night, then a
suitable pressure limiting valve must be fitted.
The boiler is designed to provide hot water on demand to
multiple outlets within the property. If there is a requirement
for greater demands, for example if the property has several
bathrooms and cloakrooms, a vented or unvented hot water
storage system may be used.
Showers
Any shower valves used with the appliance should be of a
thermostatic or pressure balanced type. Refer to the shower
manufacturer for performance guidance and suitability.
Flushing and Water Treatment
The boiler is equipped with a stainless steel heat exchanger.
The detailed recommendations for water treatment are given
in BS 7593:1992 (Treatment of water in domestic hot water
central heating systems); the following notes are given for
general guidance;
If the boiler is installed on an existing system, any
unsuitable additives must be removed;
Under no circumstances should the boiler be fired before the
system has been thoroughly flushed; the flushing procedure
must be in line with BS7593:1992.
We highly recommend the use of a flushing detergent
appropriate for the metals used in the circuit, whose function
is to dissolve any foreign matter that may be in the system.
In hard water areas or where large quantities of water are in
the system the treatment of the water to prevent premature
scaling of the main heat exchanger is necessary.
The formation of scale strongly compromises the efficiency of
the thermic exchange because small areas of scale cause a
high increase of the temperature of the metallic walls and
therefore add to the thermal stress of the heat exchanger.
Demineralised water is more aggressive so in this situation it
is necessary to treat the water with an appropriate corrosion
inhibitor.
Any treatment of water by additives in the system for frost
protection or for corrosion inhibition has to be absolutely
suitable for all the metals used in the circuit.
(continued)
The use of a corrosion inhibitor in the system is
recommended to prevent corrosion (sludge) damaging the
boiler and system;
If anti-freeze substances are to be used in the system, check
carefully that they are compatible with the metals used in the
circuit.
MTS suggests the use of suitable anti-freeze products, which
will prevent rust and incrustation taking place.
Periodically check the pH of the water/anti-freeze mixture of
the boiler circuit and replace it when the amount measured is
out of the range stipulated by the manufacturer ( 7 < pH < 8).
DO NOT MIX DIFFERENT TYPES OF ANTI-FREEZE
In under-floor systems, the use of plastic pipes without
protection against penetration of oxygen through the walls
can cause corrosion of the systems metal parts
(metal piping, boiler, etc), through the formation of oxides
and bacterial agents.
To prevent this problem, it is necessary to use pipes with an
"oxygen-proof barrier", in accordance with standards DIN
4726/4729. If pipes of this kind are not used, keep the
system separate by installing heat exchangers of those
with a specific system water treatment.
IMPORTANT
Failure to carry out the water treatment procedure will
invalidate the appliance warranty.
System Controls
The boiler is electrically controlled and is suitable for most
modern electronic time and temperature controls. The
addition of such external controls can be beneficial to the
efficient operation of the system, please refer to local
Building Regulations for further advice. The boiler
connections for external controls are 12V DC and so only
controls of 12V DC that have voltage free contacts should be
used. (Section 13 Electrical Connections - page 26).
Location
The boiler can be installed on any suitable internal wall.
Provision must be made to allow the correct routing of the flue
and siting of the terminal to allow the safe and efficient removal
of the flue products. A compartment or cupboard may be used
provided that it has been purpose-built or modified for the
purpose. It is not necessary to provide permanent ventilation
for cooling purposes. Detailed recommendations are given in
BS 5440 pt 2. If it is proposed that it is installed in a timber
framed building then reference should be made to British Gas
Document DM2, or advice sought from CORGI.
Where a room sealed appliance is installed in a room
containing a bath or shower, the appliance and any
electrical switch or appliance control, utilising mains
electricity should be situated specifically in accordance
with current IEE Wiring Regulations.
For unusual locations, special procedures may be necessary.
BS 6798:2000 gives detailed guidance on this aspect.
Condensate Discharge
The condensate discharge hose from the boiler must have a
continuous fall of 2.5 o and must be inserted by at least 50mm
into a suitable acid resistant pipe - e.g. plastic waste or
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