Control Unit; Control Unit For Constant Temperature Or Weather-Compensated Operation; Design And Functions - Viessmann VITODENS 111-W Technical Manual

Control unit

7.1 Control unit for constant temperature or weather-compensated operation

Design and functions

Design
A
2
1 3
0 4
bar
A Pressure gauge
B Display
C tw Rotary selector "DHW temperature"
Programming unit:
■ Rotary selectors:
– Menu functions at service level
– Reset function
■ Adjustment of:
– DHW temperature
– Operating program (Eco/Comfort)
– Heating curves (displacement of level)
– Codes
■ Display of:
– Boiler water temperature
– DHW temperature
– Operating data
– Diagnostic details
– Fault messages
Functions
■ In conjunction with outside temperature sensor and clock thermo-
stat (accessories) or external time switch:
Weather-compensated control of the boiler water and/or flow tem-
perature
■ Control of a heating circuit without mixer
■ Electronic maximum and minimum flow temperature limit (perma-
nently set)
■ Demand-dependent heating circuit pump and burner shutdown
control
■ Pump anti-seizing protection
■ Frost protection monitoring of the heating system (in conjunction
with outside temperature sensor)
■ Integral diagnostic system
■ Cylinder temperature controller with priority control
Control characteristics
PI characteristics with modulating output
7
Time switch
Switching times cannot be selected at the control unit.
A clock thermostat or a time switch (accessories) is required for
weather-compensated operation and to select switching times.
Setting the operating programs
Frost protection monitoring (see frost protection function) for the
heating system is enabled in all operating programs.
VIESMANN
58
B C
°C
6 0
r
A
COMFORT
D E
r
D tr Rotary selector "Heating water temperature" and "Reset"
E ON/OFF switch
The following operating programs can be selected:
■ Heating and DHW
■ Only DHW
■ Standby mode
Frost protection function
With outside temperature sensor
■ The frost protection function is switched on when the outside tem-
perature drops below approx. +5 °C.
With active frost protection, the heating circuit pump will be
switched ON and the boiler water is maintained at a lower temper-
ature of approx. 20 °C.
The DHW cylinder will be heated to approx. 20 °C.
■ The frost protection function is switched off when the outside tem-
perature exceeds approx. +5 °C.
Without outside temperature sensor
Only boiler frost protection
Summer mode
The burner starts only when the DHW cylinder needs reheating or
when DHW is drawn from a gas condensing combi boiler.
Heating curve setting (level)
In weather-compensated operation, the boiler water temperature (=
flow temperature of the heating circuit without mixer) is regulated
according to the outside temperature.
The flow temperature required to reach a specific room temperature
depends on the heating system and the thermal insulation of the
building to be heated.
Adjusting the heating curves matches the boiler water temperature
and the flow temperature to these conditions.
Heating curves:
■ The temperature limiter limits the maximum boiler water tempera-
ture.
■ The flow temperature cannot exceed the boiler water temperature.
VITODENS