Technical data

4
SECONDARY�
RETURN
COLD�
SUPPLY
CHECK�
VA LV E
SECONDARY�
CIRCULATION�
PUMP
COLD�
INLET �
CONNECTION
SWEPT�
TEE
3.0 INSTALLATION – GENERAL
(FIGS 3 & 5)
3.1 PIPE FITTINGS
All pipe ttings are made via 22mm compression
ttings directly to the unit. The ttings are threaded
3/4”BSP male parallel should threaded pipe connec-
tions be required.
3.2 COLD FEED
A 22mm cold water supply is recommended however,
if a 15mm (1/2”) supply exists which provides suf-
cient ow this may be used (although more ow
noise may be experienced).
A stopcock or servicing valve should be incorporated
into the cold water supply to enable the Santon Pre-
mier Plus and its associated controls to be isolated
and serviced.
3.3 COLD WATER COMBINATION VALVE (FIG 1)
The Cold Water Combination Valve can be connected
anywhere on the cold water mains supply prior to the
Expansion Vessel (see Fig. 5). The Cold Water Com-
bination Valve is installed as a complete one-piece
unit. The valve incorporates the Pressure Reducer,
Strainer, Expansion Valve and Check Valve. Ensure
that the valve is installed with the direction of ow
arrows pointing in the right direction. No other valves
should be placed between the Cold Water Combination
Valve and the Premier Plus unit. The Expansion Valve
connection must not be used for any other purpose.
FIG. 1 Cold Water Combination Valve
FIG. 2 Secondary circulation connection
3.4 DRAIN TAP
A suitable draining tap should be installed in the cold
water supply to the Premier Plus unit between the
Cold Water Combination Valve and the heater at as
low a level as possible. It is recommended that the
outlet point of the drain pipework be at least 1 metre
below the level of the heater (this can be achieved by
attaching a hose to the drain tap outlet spigot).
3.5 EXPANSION VESSEL
The Expansion Vessel accommodates expansion that
results from heating the water inside the unit. The unit
is pre-charged at 3.5 bar. The Expansion Vessel must
be connected between the Cold Water Combination
Valve and the Santon Premier Plus (see Fig. 5). The
location of the Expansion Vessel should allow access
to recharge the pressure as and when necessary, this
can be done using a normal car foot pump. It is recom-
mended that the Expansion Vessel is adequately sup-
ported. An Expansion Vessel wall mounting bracket
is supplied for this purpose
3.6 SECONDARY CIRCULATION
If secondary circulation is required it is recommended
that it be connected to the Premier as shown in Fig.
2 via a swept tee joint into the cold feed to the unit.
A Swept Tee joint is available as an accessory order
code no. 94 970 033.
The secondary return pipe should be in 15mm pipe
and incorporate a check valve to prevent backow. A
suitable WRAS approved bronze circulation pump
will be required. On large systems, due to the increase
in system water content, it may be necessary to t an
additional expansion vessel to the secondary circuit.
this should be done if the capacity of the secondary
circuit exceeds 10 litres.
Pipe capacity (copper)
15mm o/d = 0.13 l/m (10 litres = 77m)
22mm o/d = 0.38 l/m (10 litres = 26m)
28mm o/d = 0.55 l/m (10 litres = 18m)
Secondary circulation is NOT recommended for di-
rect electric units being used on Off Peak electricity
tariffs.
3.7 OUTLET
The hot water outlet is a 22mm compression tting
located at the top of the cylinder. Hot water distribu-
tion pipework should be 22mm pipe with short runs
of 15mm pipe to terminal ttings such as sinks and
basins. Pipe sizes may vary due to system design.
EXPANSION VALVE
COLD MAINS
CONNECTION
(22mm)
EXPANSION VALVE
OUTLET (15mm)
OUTLET
CONNECTION
(22mm)
PRESSURE
REDUCING
VALVE
HOUSING
PRESSURE
REDUCING
VALVE
CARTRIDGE (3.5 bar)