Installation & Maintenance Instructions for an unvented
hot water cylinder with internal thermal expansion
Hot Water
Energy
Storage
Unvented Cylinder
SEPT 2018
15
PRE-PLUMBED
CYLINDER INSTALLATION
COLD MAINS PIPEWORK
Run the cold main through the building to the place where the
unvented pre-plumbed unit is to be installed. Take care not to run
the cold pipe near hot water or heating pipework so that the heat
pick-up is minimized. Identify the cold water supply pipe and fit an
isolating valve (not supplied). A 22mm BS1010 stopcock can typically
be used but a 22mm quarter turn full bore valve would be better
as it does not restrict the flow as much. Do not use “screwdriver
slot” or similar valves. Make the connection to the inlet control set
(Position 2). Ensure that the arrow points in the direction of the
water flow.
CONNECTING TO THE CYLINDER
All of the pipework connections on the cylinder are suitable for
22mm copper pipe. The threads on connections are 3/4” BSP
parallel male thread. Suitable nuts and olives are provided, in
the Accessory pack. Only connect 22mm Table X copper tube to
these connections. Cut the tube with a pipe cutter and ensure no
sharp edges or burrs protrude. Slide both gland nut and olive onto
the tube and push tube fully home into the connection, ensuring
the tube end fully bottoms on the connection recess. Smear the
outer wall of the olive with plumbing paste and tighten gland nut
in the prescribed manner. Upon filling/commissioning, ensure all
connections are completely watertight.
BALANCED COLD CONNECTION
If there are to be showers, bidets or monobloc taps in the
installation then a balanced cold supply is necessary. There is a
22mm balanced connection on the inlet set.
HOT WATER PIPEWORK
Connect to HWDO (Position B on diagram). Run the first part of
the hot water distribution pipework in 22mm. This can be reduced
to 15mm and 10mm as appropriate for the type of tap etc. Your
aim should be to reduce the volume of the hot draw-off pipework
to a practical minimum so that the time taken for the hot water is
as quick as possible. Where monobloc mixing taps and showers are
used, these should be installed to comply with the Water Supply
(Water Fittings) Regulations 1999. If these devices are supplied with
un-balanced supplies there should be single check valves installed at
both inlets, to stop over pressurising of either supply.
CONNECTIONS FOR INDIRECT UNITS
Connect to the boiler flow and return (Positions E & F) lines. An
additional expansion vessel and safety valve is supplied. The boiler
may be Gas, Electric or Oil but must be under effective thermostatic
control. Uncontrolled heat sources such as some AGA’s, back
boilers, solid fuel stoves, etc. are NOT SUITABLE. Please contact our
Technical department for guidance. Connect to (Position G ) for
the radiator circuits. Twin zone heating unit are supplied with 2 port
zone valves in positions G and H
CONNECTIONS FOR SOLAR COILS
Connect to the solar coil as detailed on page 11 ensure the solar
pump is connected via the over temperature cut out as described on
page 11.
SECONDARY CIRCULATION
The unvented cylinder can be used with secondary circulation. An
appropriate WRAS approved bronze circulator should be used in
conjunction with a non-return valve to prevent backflow. On large
secondary circulation systems it may be necessary to incorporate
an extra expansion vessel into the circuit to accommodate the
increased system water volume. A secondary return boss is fitted as
standard on 210, 250 & 300 ltr units (Position D). On smaller sizes,
tee into the cold feed pipe above the drain.
IMMERSION HEATERS
The immersion heater is supplied with remotely mounted
thermostat within the heater enclosure. The thermostat switches
both live and neutral and comprises an adjustable control and a
high limit manually resettable thermal cut-out. All thermostat
connections and probe mounts are factory fitted.
The electrical supply to each immersion heater must be fused at
13A via a double pole isolating switch to BS 3456. The cable must be
1.5mm
2
3 core heat resistant (85°C HOFR) sheathed flex complying
to BS 6141:1981 Table 8. Do not operate the immersion heater/s until
the unit is full of water. Do not operate the immersion heater/s if
any sterilisation liquid is in the cylinder as this will cause premature
failure. Each immersion heater must be earthed.
Remove the thermostat cover by removing the retaining screw,
opening the cover and sliding it to the left to disengage from the
retaining clamps.
Connect to the terminal block ensuring the outer sheath is clamped
and the cables are secured without strain on any of the components
or cables.
ELECTRICAL CONNECTIONS
Warning: This appliance must be earthed and all wiring should
be completed by a competent electrician in accordance with the
latest I.E.E wiring regulations
Complete the wiring – use the appropriate wiring diagrams on page
13 - 14.
ELECTRICAL CONNECTIONS
Complete the wiring – use the appropriate wiring diagrams on pages
13 & 14.
COMMISSIONING
Carry out commissioning as per instructions on page 17 and in line
with boiler manufacturer’s instructions for the heating and the
primary circuit. Primary pipework must be filled, bled and tested in
accordance with the boiler manufacturer’s instructions, to avoid
damage to the circulation pump.
