10
Installation and Servicing
SECTION 1 - GENERAL
1.9 WATER CIRCULATION SYSTEM
IMPORTANT.
A minimum length of 1 metre of copper pipe MUST be fitted to
both flow and return connections from the HIU before connection
to any plastic piping.
The central heating system should be in accordance with
BS 7593
Code of practice for the preparation, commissioning
& maintenance of domestic central heating and cooling water
systems.
1.10 HEAT INTERFACE CONTROL
INTERLOCKS
Central heating system controls should be installed to ensure that
the HIU has no demand when there is no requirement from the
system, in compliance with Building Regulations.
Heating systems utilising full thermostatic radiator valve control
of temperature in individual rooms should also be fitted with a
room thermostat controlling the temperature in a space served by
radiators not fitted with such a valve.
When thermostatic radiator valves are used, the space heating
temperature control over a living / dining area or hallway having
a heating requirement of at least 10% of the minimum HIU heat
output should be achieved using a room thermostat, whilst other
rooms are individually controlled by thermostatic radiator valves.
However, if the system employs thermostatic radiator valves on all
radiators, or two port valves, then a bypass circuit must be fitted
with an automatic bypass valve to ensure a flow of water should
all valves be in the closed position.
1.11 ELECTRICAL SUPPLY
WARNING.
This appliance must be earthed.
Wiring external to the appliance MUST be in accordance with
the current I.E.E. (BS 7671) Wiring Regulations and any local
regulations which apply. For IE reference should be made to the
current ETCI rules for electrical installations.
The mains supply to the HIU and system wiring centre shall
be through one common fused double pole isolator and where
practical replacement installations, the isolator shall be situated
adjacent to the appliance.
0.6m
Zone 0
Recessed
window
Zone 2
Ceiling
3G8913a
2.25m
Zone 1
Compartment Installations
A compartment used to enclose the HIU should be designed and
constructed specially for this purpose.
An existing cupboard or compartment may be used, provided that it
is modified for the purpose.
Braces for compartments must be easily removable for service
access. In both cases, details of essential features of cupboard /
compartment design, including airing cupboard installation, are to
conform to the following:
BS 6798 (Temperature control ventilation is required - see ‘Air
Supply’ for details).
The position selected for installation MUST allow adequate space
for servicing in front of the HIU, this can be by means of an opening
door.
For the minimum clearances required for safety and subsequent
service, see the wall mounting template and sections below. In
addition, sufficient space may be required to allow lifting access to
the wall mounting plate.
Dependant on the size and insulation aspects of the cupboard or
room, air ventilation may be required to ensure the ambient air
around the product does not exceed 35°C. If it may exceed 35°C
then additional air vents and ventilation will be required in the room
or internal space in which the HIU is installed.
Failure to provide an ambient operational environment of less than
35°C may invalidate the warranty.
1.8 PRIMARY HEAT SUPPLY CONNECTION
The supplier of the Heat Network Energy must ensure the supply
remains within the operational requirements of the HIU fitted.
It must conform to all codes of practice.
Any additives and dosing systems must conform to the water
treatment directive for that area of installation.
Any third-party system control function (Heat Network or Credit
Control etc.) will not be the responsibility of the HIU manufacturer.
Any heat metering data collection and billing is the sole
responsibility of the metering service provider.
