Dhw Tank Temperature Control - Viessmann VITOTRONIC 200 Installation And Service Instructions Manual

Function Description, Vitotronic 300-K

DHW Tank Temperature Control

Brief description
H The DHW tank temperature control is a constant
temperature control. This is the result of starting and
stopping the circulation pump for DHW tank heating.
The switching differential is ±2.5 K.
H When the DHW tank is heated, a set supply
temperature is specified that is 20 K higher than the set
DHW temperature (adjustable via coding address "60"
in the "DHW" group).
Functions
Time program
An automatic or an individual time program may be
selected for DHW heating and the DHW circulation pump.
Compared with the heating circuit heatup phase, DHW
heating starts 30 min earlier in automatic mode.
The individual time program enables up to 4 time
phases per day to be set for DHW heating and the DHW
circulation pump for every day of the week.
All DHW tank heating sequences will be completed
independently of the time program.
In conjunction with coding address "7F" in the "General"
group
H Detached house
Code "7F:1":
– Automatic mode
The heating times for heating circuit 1 are applied
to systems with two or three heating circuits.
– Individual time program
The time phases for DHW heating and the DHW
circulation pump have the same effect on all heating
circuits.
H Apartment building
Code "7F:0":
– Automatic mode
For systems with two or three heating circuits,
the heating times for the relevant heating circuit
will be applied.
– Individual time program
The time phases for DHW heating and the DHW
circulation pump can be adjusted individually for
each heating circuit.
Priority control
H With priority control: (code "A2:2" in the "Heating
circuit..." group):
The set supply temperature is set to 32° F (0° C)
during DHW tank heating.
The mixing valve closes and the heating circuit pump
is switched off.
H Without priority control:
The heating circuit control unit continues to operate
with the same set value.
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Vitotronic 200 and 300-K Installation and Service
Frost protection
The DHW tank will be heated to 68° F (20° C) if the
DHW temperature sinks below 41° F (5º C).
Auxiliary function for DHW heating
This function is activated by providing a second set DHW
temperature via coding address "58" in group "DHW"
and activating the fourth DHW phase for DHW heating.
Set DHW temperature
The set DHW temperature can be adjusted between
50 to 140° F (10 and 60° C).
The set range can be extended up to 95º C via coding
address "56" in the "DHW" group.
The set default value of the programming unit and/or
the Vitotrol 300A remote control units can be allocated
via coding address "66" in the "DHW" group.
DHW circulation pump
This delivers hot water to the draw-off points
at adjustable times.
Four time phases can be selected at the control unit
for every day.
Auxiliary circuits
DHW heating in conjunction with the heating circuits
can be blocked or enabled by changing over the heating
program (see code "D5" in the "Heating circuit..." group).
System with primary store system
The above functions also apply in conjunction with
primary store systems.
Set the following codes:
"55:3" in the "DHW" group, "4C:1", "4E:
2" in the "General" group.
System with solar control unit
A third set DHW temperature can be specified via coding
address "67" in the "DHW" group.
The DHW tank is only reheated by the boiler if the
temperature falls below this value.