Manual mixer shower
4
TYPICAL SUITABLE INSTALLATIONS
Instantaneous gas-heated systems,
e.g. combination boilers
(fig.2)
The shower control
MUST
be installed with a
multipoint gas water heater or combination
boiler of a fully modulating design, i.e.
to maintain relatively stable hot water
temperatures.
A drop tight pressure reducing valve
MUST
be fitted if the supply pressures exceed 5 bar
running.
An expansion vessel, shown in
fig.2
,
MUST
be fitted and regularly maintained, to prevent
the shower mixer being damaged by excess
pressures. This may already be installed within
the boiler (check with manufacturer) and is in
addition to the normally larger central heating
expansion vessel.
The layout and sizing of pipework
MUST
be
such that nominally equal inlet supply pressures
are achieved and the effects of other draw-offs
are minimised.
Unvented mains pressure systems
(fig.3)
The shower control can be installed with an
unvented, stored hot water cylinder.
For systems with no cold water take off after the
appliance reducing valve, it will be necessary to
fit an additional drop tight pressure reducing
valve when the mains pressure is over 5 bar. The
drop tight pressure reducing valve
MUST
be
set at the same value as the unvented package
pressure reducing valve.
Note:
An additional expansion vessel
(fig.3)
may be required if a second pressure reducing
valve is installed. This does not apply to
packages with a cold take off after the pressure
reducing valve to the cylinder.
The layout and sizing of pipework
MUST
be
such that nominally equal inlet supply pressures
are achieved and the effects of other draw-offs
are minimised.
*Fig.2
*
(diagrammatic view – not to scale)
*
(diagrammatic view – not to scale)
*Fig.3
CH flow
Cold
mains
supply
Hot water
CH return
Service
valves
Mixer
valve
Stop
tap
Expansion
vessel
Pressure
reducing valve
Combination
boiler
Service
valves
Balanced cold mains supply
Cold mains supply
Mixer
Expansion
vessel
Pressure
reducing valves
Stop tap
Unvented
hot water
storage unit
Safety devices
not shown
