B0E Dual Mode Heat Pump Operation - Viessmann VITOTRONIC 200 Service Instructions Manual

Parameter group External heat source

7B0E Dual mode heat pump operation

Only applies to central heating.
Value Meaning
"0" Dual mode alternative operation for heating
systems with buffer cylinder:
If the adjusted outside temperature (long term
average) lies above the "Dual mode temper-
ature external heat source 7B02", central
heating will only be provided by the heat
pump, below this it will only be provided by
the external heat source.
"1" Dual mode parallel operation for heating sys-
tems with buffer cylinder:
If the adjusted outside temperature (long term
average) lies below the "Dual mode temper-
ature external heat source 7B02", the ex-
ternal heat generator can start in addition to
the heat pump. The heat pump stops at out-
side temperatures below "Shutdown limit,
heat pump dual mode 7B0F".
"2" Dual mode alternative operation for heating
systems without buffer cylinder and with only
1 heating circuit without mixer:
If the adjusted outside temperature (long term
average) lies above the "Dual mode temper-
ature external heat source 7B02", central
heating will only be provided by the heat
pump, below this it will only be provided by
the external heat source.
7B0F Shutdown limit, heat pump dual mode
If the adjusted outside temperature (long-term aver-
age) falls below this temperature limit, central heating
and DHW heating are carried out by the external heat
source alone, even with dual mode parallel operation
(for DHW heating, set "Enable external heat source
for DHW heating 7B0D" to "1").
7B10 Enable min. temp. maintenance for ext. HS
The following components for the hydraulic connection
of the external heat generator will only be switched
when the boiler water temperature of the external heat
generator has reached "Min. flow temperature mixer
external heat source ON 7B05". This prevents cold
heating water from entering the system flow or the
DHW cylinder.
Central heating:
■
External heat generator mixer opens.
■ DHW heating:
Circulation pump for cylinder reheating starts.
214
!
Information on setting "0" and "1"
In order to prevent the buffer cylinder being heated via
the return of the external heat generator, route the
heating circuit return via a 3-way diverter valve directly
into the external heat generator. Connect the 3-way
diverter valve to 212.4 on the main PCB.
Note
For DHW heating, a demand to the external heat gen-
erator in parallel to the heat pump is also made above
the dual mode temperature: See "Dual mode temper-
ature external heat source 7B02".
!
Note
■ This value should always be set lower than "Dual
mode temperature external heat source 7B02".
The setting 50
■ –
≙
Setting 1 0.1 °C
!
The characteristics of these components can be deter-
mined with the following settings, if the boiler water
temperature during the existing demand for the exter-
nal heat generator falls below the "Min. flow tempera-
ture mixer external heat source ON 7B05".
C switches off this function.
°