Digital Timer Of Operating Unit; Heating Curve Adjustment; Adjusting The Operating System; Freeze-Up Protection Function - Viessmann VITOTRONIC 200 Technical Data Manual

Structure and Operation
Structure and Operation

Digital timer of operating unit

A digital timer with day and week
feature, calendar, automatic resetting to
daylight savings time and automatic
functions for domestic hot water heating
and recirculation pump.
Time, day and standard switching times
for room heating, domestic hot water
heating and domestic hot water
recirculation pump are factory preset
(individually programmable), max. four
time switch intervals programmmable per
day.
Shortest interval: 10 minutes
Power reserve: 5 years

Adjusting the operating system

All operating programs feature freeze-up
*1
protection for the heating system.
With the program selector buttons the
following can be selected:
heating and domestic hot water
–
domestic hot water only
–
standby operation
–
*1
See Freeze-up Protection Function
below.

Freeze-up protection function

The freeze-up protection function is
activated when the outside temperature
–
drops to +34 ºF/1ºC.
The freeze-up protection function
activates the circulation pumps and
keeps the boiler water temperature at
the reduced operation setpoint level, at
a minimum temperature of approx.
68 ºF/20 ºC (for heating boilers with
low limit the respective temperature
will be maintained).
deactivated when the outside
–
temperature exceeds +37 ºF/3 ºC.
When the freeze-up protection function
is deactivated, heating boiler and
circulation pumps are turned off.
Summer economy mode
(Domestic hot water heating only,
program selector switch " ")
The burner only activates if domestic hot
water needs to be produced (as required
by DHW setpoint).
4
(continued)

Heating curve adjustment

The weather-responsive Vitotronic 200
regulates the boiler water temperature
(= supply water temperature of the
heating circuit without mixing valve) and
the supply temperature of the heating
circuit with a mixing valve.
The required supply temperature for a
certain room temperature depends on the
heating system and the insulation of the
building in question.
The adjustment of both heating curves
individually allows for the boiler water
temperature and the supply temperature
of the mixing valve circuit to be adjusted
to the respective conditions.
Heating curves:
Low temperature heating system,
e.g. radiant floor heating
Medium temperature heating system,
e.g. cast iron radiation, staple-up
radiant floor heating
High temperature heating system,
e.g. fintube radiation, fan coils
The maximum boiler water temperature is
restricted by both the adjustable high
limit and the electronic maximum
temperature limit.
The supply water temperature cannot
exceed the boiler water temperature.
Boiler water temperature sensor
Cable length 5.2 ft./1.6 m, ready to plug
in.
Maximum ambient temperature
– at operation: 32 to 266 ºF/
0 to 130 ºC
– when storing or transporting:
–4 to +158 ºF/
–20 to +70 ºC
Outdoor temperature sensor
Installation site:
– North or northwest side of building
– 6.6 to 8.2 ft./2 to 2.5 m above ground,
for multi-storey buildings mount sensor
on upper half of second storey.
Connection:
– 2-wire cable, cable length 115 ft./
35 m with a wire size of min. AWG 16
copper.
– the cable to the outdoor sensor must
not be laid near line voltage wiring
(120/240 V).
Maximum ambient temperature at
operation,
when storing or
transporting: – 40 to +158 ºF/
– 40 to +70 ºC
Domestic hot water tank temperature
sensor
Cable length 19 ft./5.8 m, ready to plug
in.
Maximum ambient temperature
– at operation: 32 to 194 ºF/
0 to 90 ºC
– when storing or transporting:
–4 to +158 ºF/
–20 to +70 ºC