System Boiler - Separate Heating And Dhw Circuits (4 Pipes) - Viessmann Vitodens 200-W Installation Instructions Manual

Electrical connections
Separate hydraulic connections for DHW
cylinder and heating circuits (4 pipes).
• The Viessmann low voltage DHW
cylinder sensor must be used.
• The low voltage DHW cylinder sensor
must be attached to the cylinder by
secure means to ensure good contact
is made with the cylinder itself, not the
insulation, or fitted into a purpose made
pocket.
• The low voltage DHW cylinder sensor
connects to plugs in the cable harness
pictured on page 56.
• Connect permanent mains supply and
room thermostat (as combination boiler
previous page).
Note
If the Vitotronic HC2 controller is
upgraded to allow for weather
compensation the instructions for this
option are supplied with the replacement
controller and outside sensor kit.
• The DHW will always take priority over
the central heating when timed demand
is selected.
• Time the heating and DHW via the
integral Vitotronic HC2 controller.
48
(cont.)
Note
Where an unvented hot water cylinder
is used the safety thermostat connected
to the cylinder that controls the 2-port
safety valve (requirement for G3 of the
building regulations) can be operated by
an independent remote timer or via an
internal H1 or H2, or external H1
Viessmann accessory.
Along with other functions the H1, H2,
internal /H1 external accessories when
connected provide the option of a timed
240V output. Follow the installation
instructions supplied with the accessory.
Plug 28 on the H1 extension must be used
to connect the 2 port safety valve via the
cylinder high limit thermostat. The
Vitotronic internal boiler control must be
set to external cylinder loading pump to
activate the timed 240V supply.
This is done via coding address 53 in
coding 2.
Note
A Vitotrol 100 UTA/D can be connected to
plug 96, however the integral Vitotronic
HC2 7 day controller would require the
central heating to be set to permanently
on, please refer to user guide.