Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 83

Vitotronic 200 and 300-K Installation and Service
DHW Tank Temperature Control
Control sequence
Set code "55:0" in the "DHW" group, DHW tank heating
The DHW tank goes cold (set value −2.5 K; change via
coding address "59"):
H The common set supply temperature is set 20 K higher
than the set DHW temperature (change via coding
address "60").
The DHW tank is hot, (set value+2.5 K):
H The common set supply temperature is returned to the
set weather-compensated value.
H Pump run-on:
The circulation pump runs on after DHW tank heating
until one of the following criteria are met:
- The weather-compensated set supply temperature
has been reached.
- The set DHW temperature is exceeded by 5 K.
- The set max. run-on time is reached (coding address
"62").
H Without pump run-on (code "62:0")
Code "55:1" in the "DHW" group, adaptive DHW tank
heating
With adaptive DHW tank heating, the speed of the
temperature rise during DHW heating is taken into
account.
The DHW tank goes cold (set value −2.5 K; change
via coding address "59"):
H The common set supply temperature is set 20 K higher
than the set DHW temperature (change via coding
address "60").
The DHW tank is hot:
H The control unit checks whether the boiler will
be required to supply heating energy after the
DHW tank has been heated up or whether residual
boiler heat should be transferred to the DHW tank.
Accordingly, the control unit determines the burner
and circulation pump stop times to prevent the set
DHW temperature being substantially exceeded after
the DHW tank has been heated up.
Function Description, Vitotronic 300-K
(continued)
Code "55:2" in the "DHW" group, DHW tank temperature
control with 2 DHW tank temperature sensors
DHW tank temperature sensor 1 enables the circulation
pump for DHW tank heating and is evaluated for stop
conditions during the pump run-on time.
DHW tank temperature sensor 2:
The DHW tank heating will be switched on early if a lot
of hot water is drawn off. The DHW tank heating will be
switched off early if no hot water is drawn off.
DHW tank goes cold:
H Set value −2.5 K, adjustable via coding address "59"
or
H Actual DHW temperature at sensor 2 < set DHW
temperature x factor for start time (adjustment via
coding address "69")
The DHW tank is hot:
H Set value +2.5 K
and
H Actual DHW temperature at sensor 2 > set DHW
temperature x factor for stop time (adjustment via
coding address "68")
Code "55:3" in the "DHW" group, DHW tank temperature
control, primary store system
The DHW tank goes cold (set value −2.5 K; change
via coding address "59"):
H The common set supply temperature is set 20 K higher
than the set DHW temperature (change via coding
address "60").
H The primary pump in the primary store system starts.
H The 3-way mixing valve opens and then regulates
to the defaulted set value.
H The circulation pump for DHW tank heating cycles
(short term ON and OFF) until the set supply
temperature has been reached (set DHW temperature +
5 K). Then it runs constantly.
If, during heating, the actual value falls below the
required set temperature, the circulation pump for DHW
tank heating will temporarily cycle again.
The DHW tank is hot:
H (DHW tank temperature sensor 1:
actual value ≥ set value
and
DHW tank temperature sensor 2:
actual value > set value −1.5 K):
H The common set supply temperature is returned
to the set weather-compensated value.
H The circulation pump for DHW tank heating stops
immediately when the 3-way mixing valve is fully
opened.
or
H The circulation pump for DHW tank heating stops after
expiry of the run-on time that is selected via code "62"
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