Viessmann Vitodens 200 Technical Manual page 58

2.1 General installation recommendations
System design
Viessmann condensing boilers can
generally be installed in any pumped hot
water heating system (sealed system).
There are no applicable special
standards.
The circulation pump is an integral part of
the Vitodens up to 35 kW.
For the Vitodens 300 from 49 kW output,
the circulation pump (BUS pump) is
available as an accessory and may be
installed either inside the boiler casing or
externally.
Minimum system pressure 0.8 bar.
The boiler water temperature is limited
to 74 ºC.
To minimise distribution losses, we
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recommend that you size the heat
distribution system to a max. flow
temperature of 70 ºC.
For apartments with less than 80 m
for low energy houses with low heating
demand we recommend, due to the direct
capturing of the room-influencing factors,
to utilise the Vitodens with a constant
temperature control unit in conjunction
with the Vitotrol 100, type UTA or UTD.
To reduce the burner cycling in low
energy houses with a correspondingly
lower heat demand, we recommend
using a low loss header, a three-way
mixer or a Vitodens 300, 333 or 343
with 4.2 kW to 13 kW output.
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Low water indicator
According to EN 12828, special low water
level protection can be omitted for boilers
up to 300 kW, as long as heating can be
reliably prevented when the water level is
too low.
Viessmann Vitodens boilers are equipped
with a low water indicator (boil-dry
protection). Tests have verified that the
burner will be automatically switched OFF
in the event of water shortage due to a
leak in the heating system and
simultaneous burner operation, before
the boiler or flue gas systems reach
unacceptably high temperatures.
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or
System renovation
For the Vitodens 200 and 300 up to 35 kW
output, third party adaptors are available
as accessories.
This enables the adaptation of existing
water connections for central heating
boilers of type Thermobloc-VC/VCW and
Cerastar-ZR/ZWR to Vitodens (see
chapter 2.4).
VITODENS