Central Heating With Booster Heaters - Viessmann VITOTRONIC 200 Service Instructions Manual

Function description
Heating circuits/cooling circuits
Frost protection
The frost protection function for one heating/cooling
circuit is only active when central heating is switched
off by the "Only DHW" or "Standby mode" operating
program, or when operating status "Standby" is set in
the time program. The "Standby" operating status is
set if no time phase is active in the time program.
Central heating is active if one of the following condi-
tions is met:
■ Short term average outside temperature falls below
the frost protection limit. This frost protection limit is
factory-set.
■ Room temperature falls below 5 °C (parameter
"Remote control 2003" set to "1").
■ System flow temperature falls below 5 °C.
In the case of frost protection, the heating circuit
pumps and the secondary pump are started alongside
the heat pump.

Central heating with booster heaters

See also chapter "Booster heaters" on page 37.
If the following criteria are all met simultaneously, the
heat pump control unit will send a demand to either the
external heat generator or the instantaneous heating
water heater while the central heating is on:
■ Heating circuit flow temperature remains below the
set flow temperature for more than 4 h.
■ With activated room temperature hook-up, the room
temperature is more than 0.5 K below the set room
temperature.
Booster heaters are enabled for central heating. The
■
respective start criteria are met:
– External heat generator: See page 38.
– Instantaneous heating water heater: See page 40.
Central heating with ventilation unit (supply air heating)
See page 63.
Cooling via a separate cooling circuit
Note
On systems with heating water/coolant buffer cylinder,
central cooling via a separate cooling circuit is not pos-
sible.
54
(cont.)
Heating for frost protection ends if all of the following
criteria are met:
■ Short term average outside temperature exceeds the
frost protection limit by at least 2 K.
■ Room temperature exceeds 7 °C (parameter
"Remote control 2003" set to "1").
System flow temperature exceeds 15 °C.
■
Note
The frost protection limit is factory-set to 1 °C. This set-
ting can only be changed by a heating contractor certi-
fied by Viessmann.
In order to prevent pumps switched by the heat pump
control unit from seizing up, these pumps start daily
from 13:00 h in sequence for 10 s (pump kick). The cir-
culation pump for cylinder heating or the 3-way diverter
valve "Heating/DHW" start daily at 0:00 h for 30 s.
Note
"Priority ext. heat source/instant. heating water
heater 7B01" specifies which booster heater is
switched on first for central heating. Both booster heat-
ers are switched on simultaneously for frost protection
of the heating circuits.
Only possible if no cooling takes place via a heating
■
circuit (parameter "Cooling circuit 7101").
■ There must always be 1 room temperature sensor
installed:
– Remote control room temperature sensor
("Remote control cooling circ 7116")
or
Room temperature sensor connected separately to
–
the control unit ("Ranking room temp sensor
separate cooling circuit 7106").