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HOT WATER PIPEWORK
The majority of the hot water distribution pipework should be 22mm, possibly reduced to 15mm or 10mm
dependant on the type of tap. Keep the hot draw o pipework to a minimum to maximise the transfer
speed of hot water from cylinder to outlet. UK Cylinders would advise against soldering tappings
immediately to the hot water drawo, as this reduces any inherent risk of ux landing on the immersion
heater and causing long-term corrosion to the connection and unit.
If the balanced cold connection is not provided, do not use monobloc mixer taps or showers. This would
cause the unit to back pressurise and result in discharge. Ensure that the top of the vessel is accessible for
servicing.
SECONDARY CIRCULATION
Seconday return connections are supplied as standard on 210-300 litre indirect cylinders only. Where
secondary circulation is unavoidable for smaller capacity cylinders, a circulator suitable for potable water
must be used in conjunction with a non-return valve to prevent backow. The return connection should be
made with a swept tee into the cold feed pipework directly above the drain connection. It may be necessary
to incorporate an extra expansion vessel into the circuit to accommodate an increased system volume in
larger secondary circulation systems.
pressure reducing valve must be installed into the cold supply of any such mixed tting, suitably positioned
so as to not compromise water ow to the cylinder. An outside hose tap may still be connected direct to the
incoming cold supply if desired.
IMMERSION HEATER
All standard supply is with immersion heater elements of 3 Kilowatt output at 240 Volts, Incoloy elements,
double pole thermal isolation and a 1¾” BSP threaded head.
ELECTRICAL CONNECTION - 3kW
This appliance must be earthed. It is suitable for a 240 volt A.C. supply only. The electrical installation should
only be carried out by a suitably qualied electrician in accordance with latest I.E.E. regulations. Ensure the
electrical supply is isolated before working on the system.
The electrical supply to each immersion heater must be fused at 13A via a double pole isolating switch with
a separation of at least 3mm to both poles to BS 3456.
The cable must be 2.5mm2heat resistant (85°C HOFR) sheathed ex complying to BS6141:1981 Table 8. Do
not use a cable of lesser rating.
For immersion heaters other than 3kW consult wiring requirements supplied with the immersion heater.
Do not operate the immersion heater(s) until the unit is full of water. If any sterilization liquid is in the cylin-
der do not operate the immersion heater(s) as this will cause premature failure.
This device must be earthed.
Earth connection, (green & yellow), should be made rmly to the earth post marked “E”, using the
terminal attachments provided. Live connection, (brown), from the mains supply cable to the thermostat
terminal marked “L”. Neutral connection, (blue), from the mains supply cable to the thermostat terminal
marked “N”.
PRIMARY COIL CONNECTIONS
¾” BSP connections are provided for the primary circuit which must be positively pumped. Primary ow and
return connections are interchangeable to suit site conditions. This will not aect reheat times.
Ensure a corrosion inhibitor suitable for stainless steel coils is used in conjunction with the primary circuit.
Sealed or vented primary circuits comply with normal installation practices. Although the coil is capable of
handling 7.0bar pressure, the primary pressure should exceed no more than 3.0bar. The boiler used must be
sure to have an eective thermostatic control – uncontrolled heat sources such as solid fuel stoves, AGAs etc
may not be suitable. If in doubt, please seek guidance from ourselves. The two-port zone valve should be
installed on the primary return pipework leading back to the boiler. The direction of the ow arrow should
align with the primary ow connection. The maximum operating temperature of primary coils should be
85C.
Extra thermostat bosses come supplied on any twin coil solar cylinder.
