Viessmann VITOLIGNO 300-C Installation And Service Instructions Manual page 129

Vitoligno 300-C Installation/Service
Control Functions
Supply temperature control
Example for outdoor temperature 5°F (−15°C)
Underfloor heating system, slope 0.2 to 0.8
A
Low temperature heating system, slope 0.8 to 1.6
B
Heating systems with a boiler water temperature in
C
excess of 167°F (75°C), slope greater than 1.6
Room temperature
In conjunction with the remote control and room
temperature hook-up (coding address "B0"):
Compared to the outdoor temperature, the room
temperature has a greater influence on the set supply
temperature (change via coding address "B2").
DHW temperature
The priority control of the tank heating can be adjusted
individually for each heating circuit. Adjustment via code
A2, heating group, for each heating circuit. This is used
to determine which heating circuit is affected by priority
control during tank heating.
With priority control:

During tank heating, the set supply temperature of
the relevant heating circuits is set to 32°F (0°C).
The mixing valve closes. The heating circuit pump is
switched off.
Without priority control:

The heating circuit pump continues to operate with
the same set value.
With reduced priority control:

During tank heating, the set supply temperature of
the relevant heating circuits is set to the set value of
reduced heating mode.
(continued)
Upper control range limit
Electronic maximum temperature limit
Setting range: 34°F to 260°F (1°C to 127°C)
Heating circuit pump logic (economy mode)
The heating circuit pump is switched off [set supply
temperature set to 32°F (0°C)] when the outdoor
temperature exceeds the value selected via coding
address "A5".
Extended economy mode
The heating circuit pump is switched off and the set
supply temperature is set to 32°F (0°C) if one of the
following criteria is met:
The outdoor temperature exceeds the value selected

via coding address "A6".
The set room temperature is reduced via coding

address "A9".
The mixing valve has been closed for 12 minutes

(mixing valve economy function, coding address "A7").
The actual room temperature exceeds the value

selected via coding address "B5"
Frost protection
If the outdoor temperature falls below +34°F (+1°C),
a supply temperature of min. 50°F (10°C) is ensured.
For changes see coding address "A3", variable frost
protection limit.
Upper control range limit
Electronic maximum temperature limit
Setting range: 34°F to 260°F (1°C to 127°C)
Change via coding address "C6".
Note: The maximum temperature limit is no substitute for
the underfloor heating system temperature limiter.
Temperature limiter for underfloor heating:
The temperature limiter switches the heating circuit
pump off if the set value has been exceeded. The supply
temperature is only slowly reduced in this situation, i.e.
it may be several hours before the system restarts
automatically.
Lower control range limit
Electronic minimum temperature limit
Setting range: 34°F to 260°F (1°C to 127°C)
Change via coding address "C5".
Only enabled during operation with standard room
temperature.
Function Description
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