NEO
fl
o
Water
Heater
10
September
2015
UNVENTED WATER SUPPLY
(Fig. 4.1)
Unvented Systems should only be
fi
tted by an Approved
Installer
When using the Heater on an unvented hot water stor-
age system, the Unvented System Kit, part number B314,
available from Andrews Water Heaters
must
be
fi
tted. See
Parts List Page 25.
When used in an unvented system, the heater will supply
hot water at 3½ bar or the pressure available at the mains
feed if this is lower. During conditions of no-
fl
ow, system
pressure may rise to a maximum of 6 bar, whilst the burner
is operating. When testing the system, it is recommended
that a maximum test pressure
of 7bar
is employed.
A 25 litre expansion vessel is suitable for the stored vol-
ume of all models of the heater and an average pipework
system.
FOR SYSTEMS WITH LARGER PIPE VOLUMES OR ADDI-
TIONAL STORAGE, EXPANSION VESSELS WITH GREATER
CAPACITY ARE AVAILABLE.
Assemble the components of the unvented system kit as
shown in Fig. 4.1.
IMPORTANT
When assembling the Pressure Reducing Valve and Double
Non-return Valve, ensure that the
fl
ow arrows marked on
the
components are pointing in the direction of
fl
ow i.e.
towards the heater.
Th
e relief valves
fi
tted to this appliance must not be used
for any other purpose.
No
fi
tting should be installed between the expansion valve
and the cylinder.
Th
e cold water for services may be drawn from the 22mm
compression port on Pressure Reducing Valve.
Th
e water
pressure at this point will be similar to that available at
the hot water outlet of the water heater. If this port is not
used, it should be sealed with the blanking plug supplied.
If higher
fl
ow rates are required for the cold water services,
a suitable tee
fi
tting should be
fi
tted to the pipework,
upstream of the Pressure Reducing Valve.
Th
e pipework
fi
tted to the tundish outlet should be at least
28mm diameter and made of metal it should be terminat-
ed at a suitable drain (see Building Regulations Approved
Document G3).
All
fi
ttings and materials supplying water to the storage ves-
sel must be suitable for use with drinking water and listed
in the current Water Research Centre “Materials and Fittings
Directory”.
Installation of unvented hot storage water systems must
comply with Part G of Schedule 1 of the Building Regula-
tions.
CONDENSATE DRAIN
Condensation is formed in the heater and this must be con-
tinuously discharged into a drain.
Th
is can be acomplished
by a drop of around 5 mm for every 100 mm of pipework. A
trap is supplied which should be connected into a drain via a
tundish or air break.
(Figs.5.1, 5.2, 5.3, 5.4)
Th
e condensate
fl
ow must not be allowed to block otherwise
the heater will fail to work correctly.
NOTE
An air break is required downstream of the trap to protect
the Heater from blockages and subsequent damage.
Th
e ap-
pliance can produce up to 2 litres of condensate per hour.
Never discharge the condensate into a sink, bath, bidet or
toilet etc.
Th
e condensate trap must be connected in a minimum
diameter of 19 mm plastic pipe inside a building.
External
pipework and that passing through a wall to the outside
should be run in a min of 32mm diameter. All external pipe-
work should be insulated to protect against frost.
Th
e length of external drain pipe should be kept as short as
possible and not more than 3m.
Содержание NEOflo SC25/200
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