Ariston CLAS HE R 12 Installation And Servicing Instructions page 15

Flushing and Water Treatment
The boiler is equipped with a stainless steel heat
exchanger.
The detailed recommendations for water treatment
are given in BS 7593:199 (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 BS
7593:199.
We highly recommend the use of a flushing
detergent appropriate for the metals used in the
circuit. These include cleansers produced by Fernox
BetzDearbon, 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 water to
prevent premature scaling of the main exchanger is
necessary.
The formation of scale compromises the efficiency
of the thermic heat exchanger because small areas
of scale cause a high increase in 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 metals used in the
circuit.
The use of a corrosion inhibitor in the sysem such
as Fernox MB-1, BetzDearborn Sentinel X100 or
Fernox System Inhibitor 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 such as Fernox ALPHI 11, which will
prevent rust and incrustation taking place.
Periodicaly check the pH balance 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 476/479. 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 guarantee.
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. The boiler connections for external controls
are 40V.
MTS supply a range of wired and wireless system
controls. Contact your supplier for more details.
Location
The boiler can be installed on any suitable internal
wall (suitable sound proofing may be required when
installing onto a stud partition wall). Provision
must be made to allow for 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 built or modified for this purpose. It
is not necessary to provide permanent ventilation
for cooling purposes. Detailed recommendations
are given in BS 5440 Part . If it is proposed that it
is to be installed in a timber framed building then
reference should be made to British Gas Document
DM, IGE/UP/7 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.
installation
15