7
Dual control built-in thermostatic mixer shower
Unvented Mains Pressure Systems
(g.4)
The mixer shower 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
t 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 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.
Mains Pressurised Thermal Store Systems
(g.5)
Packages of this type, tted with a tempering
valve (blender valve) can be used. A drop tight
pressure reducing valve MUST be tted if the
supply pressures exceed 5 bar running.
An expansion vessel MUST be tted and
regularly maintained, to ensure the unit is not
damaged by excess pressures. This may already
be installed externally or internally within
the thermal store (check with thermal store
manufacturer).
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
Kit
*Fig.4
Blender
valve
Flow
Cold mains supply
Hot
water
Stop tap
Expansion
vessel
Pressure
reducing valve
Return
Service
valves
Mixer
Boiler
Kit
*Fig.5
*Diagrammatic view – not to scale.
For illustration purposes only.
*Diagrammatic view – not to scale.
For illustration purposes only.