14 Durability
The system is manufactured from durable
materials and conventional plumbing components
and will have a life equal to that expected of a
vented system. It may be necessary to replace
some of the system components, eg the immersion
heater, thermostat (see section 12.2 and Detail
Sheet 2).
Installation
15 The installer
15.1 It is essential, for reasons of safety and
performance, that the installation, commissioning
and maintenance of the system is carried out by a
person with suitable training and practical
experience. However, the assessment of training
arrangements and continuing competence of
installers falls outside the scope of this Certificate.
15.2 It is the view of the Department of
the Environment, and stated in its Approved
Document G3, that, to meet the
requirements of the Building Regulations (England
and Wales) concerned with unvented hot water
storage systems, installations should be
undertaken by a
competent person
, defined as
‘one holding a current Registered Operative
Identity Card for the installation of unvented
domestic hot water storage systems, issued by the
Construction Industry Training Board (CITB), the
Institute of Plumbing, the Association of Installers of
Unvented Hot Water Systems (Scotland and
Northern Ireland), or an equivalent body’.
15.3 In Scotland, it is the requirement of
the deemed-to-satisfy provision to Technical
Standard P3.1
Unvented Hot Water
Storage System
for compliance with Regulation 28
of the Building Standards (Scotland) Regulations
that such systems be ‘in the form of a proprietary
unit or package which is: (i) the subject of a
BBA Certificate, or (ii) Kitemarked to BS 7206 :
1990’. The Standard contains no specific
requirements for installers but the Certificates
referred to state that installation must be
undertaken by a
competent person
, as defined in
section 15.2.
15.4 In Northern Ireland, it is the
requirement of Regulation P5
Unvented
Hot Water Storage Systems
that systems
with a capacity not greater than 500 litres, and
a heat input not greater than 45 kW, be certified
as meeting the relevant requirements of
Regulation P5 by a member body of EOTA
operating a Technical Approvals Scheme, eg
by the BBA under MOAT No 38 : 1986.
Agrément Certificates will refer to a need for
installation by a
competent person
, as defined in
section 15.2.
16 Conditions
The following conditions abstracted from the
Certificate holder’s instructions must be observed:
(1) The system must be connected to a water
supply with a pressure not exceeding 12 bar and
of a quality supplied by a water undertaker under
the Water Byelaws and Water Regulations, as
appropriate.
(2) The combined temperature and pressure relief
valve tundish must be in a clearly visible position
within 500 mm of the cylinder and in the same
compartment as the cylinder. The discharge pipe to
and from the tundish must be of metal and laid to
fall. It must terminate at a visible safe place, such
as a gully, where there is no risk of contact with the
hot water by persons in or about the building.
Further details are given in BBA Information
No 33 : 1989
Unvented Hot Water Storage
Systems —Hot Water Discharges from Safety
Devices. BBA Requirements and Guidance.
(3) The discharge pipe from the expansion valve
should be laid with a continuous fall to terminate in
a suitable location. The details applying to
discharge pipes given in BBA Information No 33 :
1989 are generally recommended.
(4) The system is installed in locations similar to
those for storage cylinders used in a conventional
vented system or in other locations advantageous
to the building designer (see Table 1 for load
weight of the system when ‘full’). It is important to
ensure there is adequate clearance for the removal
of the immersion heater and the corrosion
protection anode (see Table 1).
(5) Electrical wiring must be carried out in
accordance with the IEE Wiring Regulations. The
immersion heater circuit must be protected by a
suitably-rated fuse and an isolating switch with
double pole disconnection.
17 Procedure
Summary of installation procedure
17.1 The storage cylinder is located in position
(see the
Kwikot Technical Information and Installers
Instructions
and the plumbing connections made to
the inlet and outlet pipes in the same manner as for
a conventional storage cylinder, except that the
water supply pipe is taken directly from the mains
or other suitable potable supply, via the line
strainer and cold water control valves (ensuring the
arrow markings on the components are pointing
downstream) to the cold water inlet of the storage
cylinder (see Figure 2). Where balanced pressures
are required, the cold water draw-off is connected
as shown in Figure 2, using components supplied
by the Certificate holder.
17.2 The discharge pipe is connected to and
from the tundish to a safe and visible termination
point [see sections 16(2) and (3)]. The air gap at
the tundish must remain clear.
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