HEATING/PRIMARY SYSTEMS
The boiler and primary/heating systems
should be sized and installed in accordance
with BS 5449.
SAFETY
Xstream is fitted with a Pressure Relief
Valve to cope with any increase in system
pressure above the design limitations, and
a Temperature Relief Valve to provide an
adequate safety factor when used with boilers
up to 45kW output.
The primary water temperatures should be
controlled as outlined below.
PRIMARY CIRCUIT
It is essential that the circuit between the boiler
and the Xstream is pumped. The motorised
zone valve supplied should be fitted adjacent
to the unit and controlled by the cylinder
thermostat supplied. The thermostat and
motorised valve must be wired so that they
both switch off should an overheat situation
develop. It is important to follow the wiring
diagram in the Wiring Section of these
instructions.
SEALED PRIMARY CIRCUIT
Any boiler used must be of a rated output of
less than 45kW and must be fitted with an over
temperature cut-out.
Unvented primary circuits may be filled
or replenished by means of a temporary
connection between the circuit and a supply
pipe provided a ‘Listed’ double check valve
or some other no less effective backflow
prevention device is permanently connected
at the inlet to the circuit and the temporary
connection is removed after use.
Boiler
Boiler
Expansion
vessel
Safety Valve
Gauge
Pump
Pump
Motorised
Valve
Motorised
Valve
Motorised
Valve
(Energy
cut-out)
Motorised
Valve
(Energy
cut-out)
Schematic Open Vented Primary System
Schematic Sealed Primary System
Page 12
INSTALLATION