Dual control mixer with diverter
5
pressures are achieved and the effects of other
draw-offs are minimised.
c) Mains pressurised thermal store
systems
(fig.4)
Packages of this type, fitted with a tempering
valve (blender valve) can be used. A drop tight
pressure reducing valve MuST be fitted if the
supply pressures exceed 5 bar running.
An expansion vessel (shown in
fig.4
) MuST be
fitted, 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).
d) Pumped gravity fed systems
(fig.5)
The shower control MuST be fed from a cold
water cistern and hot water cylinder providing
nominally equal pressures.
The mixer unit may be used with a gravity
fed system with a pump to boost pressures as
shown
(fig.5)
.
note:
Refer to Pump instructions for pressure
requirements
INStANtANeoUS WAter heAterS
APPlIANce cAPAbIlItIeS
In order to provide the best performance
from the shower when connected to an
instantaneous water heater, the appliance must
be capable of raising the temperature of the
incoming water to a minimum of 52°C (125°F)
and delivering a flow rate of not less than eight
litres per minute.
Blender
valve
Flow
Cold mains supply
Hot
water
Stop tap
Expansion
vessel
Pressure
reducing
valve
Return
Service
valves
Mixer
Boiler
Fig.4
(diagrammatic view — not to scale)
Hot water
cylinder
Mixer
Service
valve
Cold supply
Hot supply
Cold
water
mains
supply
Ring main
Drain
valve
Isolating switch
or pull cord switch
(both fused at 3A)
Gate
valve
Service
valve
Other
draw-offs
Stopvalve
Cold water
cistern
Pump
Alternative
supply
Minimum
head
Fig.5
(diagrammatic view — not to scale)
