5.2.3
Hard water area
Important
Only water that has NOT been artificially softened must be used
when filling or re-pressurising the primary system. If the mains
cold water to the property is fitted with an artificial softening/treat
ment device the source utilised to fill or re-pressurise the system
must be upstream of such a device.
5.2.4
Bypass
The boiler utilises the primary side of the DHW plate heat exchanger as an
automatic integral bypass.
5.2.5
System control
Further external controls (e.g. room thermostat sensors) MUST be fitted to
optimise the economical operation of the boiler in accordance with Part L
of the Building Regulations. A range of optional controls is available. Full
details are contained in the relevant Sales Literature.
Any proprietary OpenTherm control MUST allow individual adjustment of
CH and DHW temperature.
5.2.6
Treatment of water circulating systems
All recirculatory water systems will be subject to corrosion unless an ap
propriate water treatment is applied. This means that the efficiency of the
system will deteriorate as corrosion sludge accumulates within the system,
risking damage to pump and valves, boiler noise and circulation problems.
When fitting new systems flux will be evident within the system, which can
lead to damage of system components.
BS 7593 gives extensive recommendations on system cleansing and wa
ter treatment.
All systems must be thoroughly drained and flushed out using appropriate
proprietary flushing agent.
A suitable inhibitor must then be added to the system.
All system additives (flushing agents, cleansers, inhibitors etc.) must com
ply with the requirements of BS 7593. Full instructions are supplied with
the products and for further information contact the additive manufacturer
directly or consult their website.
5 Before installation
2
3
Important
Any wiring to the boiler, from either the mains or an external
control, MUST be cable of the following specification:- 0.75mm
3183/4/5Y (depending on installation) multi strand flexible cable
conforming to BS 50525-2-11.
Cable of the above specification is sufficiently flexible to with
stand normal regular opening and closing of the facia/control
box as expected during routine servicing and other maintenance
work.
Use ONLY cable glands supplied with the boiler, or provided as
spares by the manufacturer.
Under no circumstances must solid core cable be used as it is
not intended for applications where movement may occur. The
use of solid core cable could result in situations potentially haz
ardous to health.
These points must be considered when initially wiring the boiler
to the installation, and if replacing any wiring during the service
life of the boiler.
Combi 2
