Viessmann Vitodens 100-W WB1B Series Installation And Service Instructions Manual page 43

Vitodens 100-W, WB1B Installation & Service
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 49 in this manual for details on the low-
loss header.
Maximum Flow Rates
Model WB1B
∆ t
Output Btu/h
30º F rise (GPM)
35º F rise (GPM)
40º F rise (GPM)
(continued)
26 35
83,000 108,000
5.5 ----
4.7 6.2
4.2 5.4
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.
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.
Connections
43