Viessmann Vitocell 200 Cylinder Design, Installation, User & Servicing Instructions page 15

Schematic Open Vented Primary System
Warming/Overflow
Pipe
Minimum
distance as
required by
boiler
manufacturers
instructions
Pump
150mm max.
Boiler
Schematic Sealed Primary System
Expansion
Vessel
Safety Valve
Gauge
Pump
Boiler
Viessmann 4-pipe System
Note
Energy cutout devices fitted
in the Viessmann boiler
Boiler
F & E Cistern
Motorised Valve
(Energy cut-out)
Motorised Valve
Motorised Valve
(Energy cut-out)
Motorised Valve
Page 15
iNSTALLATiON
Heating/primary Systems
The boiler and primary/heating systems should be
sized and installed in accordance with BS 5449.
Safety
Viessmann Vitocell 200 Cylinder is fitted with a
Combined Temperature/Pressure Relief Valve to
cope with any increase in system temperature
and pressure above the design limitations,
when used with boilers up to 45kW output,
which is the maximum allowed by section G3
of the Building Regulations. The primary water
temperatures should be controlled as outlined
below.
Primary Circuit
It is essential that the circuit between the boiler and
the Viessmann Vitocell 200 Cylinder 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 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. Alternatively,
a CA device can be used, which will allow the
system to be permanently connected to the
cold mains supply. The primary system can
then be topped up, when required, in the same
way as an open vented system fitted with an
F&E Cistern.
4-Pipe System
If the Vitocell 200 is installed with a Viessmann
Vitodens condensing system boiler then it is
recommended to install the system to a 4-pipe
system as shown in the diagram opposite.
The Viessmann Vitodens system boilers are
operating on sealed primary circuit and are
factory fitted with an integral diverter valve,
PRV and expansion vessel and suitable energy
cut-out device to comply with G3 requirements.
If any Vitodens system boiler is installed with a
Vitocell 200, an additional DHW cylinder sensor
kit (7179 114) is required.