Viessmann VITODENS 100-W WB1B Series Installation And Service Instructions Manual page 33

Installation Examples
System Layout 4
Installation of heating circuits:
- radiator heating circuit (high
temperature circuit)
- underfloor heating circuit with 3-way
mixing valve (low temperature
circuit)
- DHW production with the following
flow conditions:
The flow rate of the heating circuits
is greater than the maximum possible
water flow rate of the Vitodens 100
boiler.
The use of a low-loss header is
therefore recommended.
A low-loss header is available as an
accessory part.
The radiator heating circuit is supplied
by a circulation pump (field supplied).
The underfloor heating circuit is
supplied by a circulation pump
installed on site which is controlled by
the extension kit. The DHW pump is
field supplied.
Note:
The use of a low-loss header is
recommended if the water flow rate is
less than 1.7 GPM / 400 L/h or more
than 6.2 GPM / 1400 L/h.
The low-loss header is available as
accessory part. See page 36 in this
manual for details on the low-loss
header.
(continued)
Note 1
Optional high limit safety control of
heating circuit E.
(During DHW production with DHW
terminal activated, the boiler supply
temperature will be set automatically
to 172º F / 78º C).
The heating system must be protected
from excessive temperature if no
automatic mixing valves are used or
no DHW priority is required.
After the DHW call for heat is
satisfied, there is a 20 second pump
post-purge time.
Maximum Flow Rates
Model WB1B 26
∆ t
Output Btu/h
30º F rise (GPM) 5.5
35º F rise (GPM) 4.7
40º F rise (GPM) 4.2
Note 2
The heating circuit pump logic output
of the Vitotronic 050 is used to
energize the RT (room thermostat)
output of power / pump module.
Therefore, using a room thermostat
in series with RT (room thermostat)
input of the boiler will reduce
unnecessary calls initiated by the
pump logic output of the Vitotronic to
the Vitodens 100 boiler (mixing valve
heating circuit only).
Note 3
During DHW call for heat, there is
no priority on mixing valve heating
circuit.
35
83,000 108,000
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6.2
5.4
Boiler Connections
33