Changing The Heating Pattern Of The Boiler - Viessmann VITOTRONIC 300 GW2 Operating Instructions And User's Information Manual

Changing the heating pattern of the boiler

The heating pattern of the boiler is influenced by the outdoor temperature and
the settings of the "shift" and "slope" of the "heating curve". Heating curves
represent the relationship between the outdoor temperature and the boiler water
or supply temperature. Put simply: The lower the outdoor temperature, the
higher the boiler water or supply temperature.
You can change the setting of the heating curve, if you establish over a prolonged
period during the heating season, that the room temperature does not meet your
requirements.
Please observe the difference in the heating pattern over a sufficiently long period
before altering the settings again.
Short-term changes in the room temperature are carried out with the "ts"
selector knob or with the "tm" button (see "Changing the room temperature" on
page 8).
Please note:
In the factory settings, the slope is set to 1.4 and the shift to 0.
The heating curves shown apply to the following settings:
"Shift of heating curve" = 0
With a different shift setting, the curves are shifted parallel in a vertical
direction.
"Normal room temperature s" = approximately 20°C / 68°F .
Please see back of manual for conversion chart.
The slope of the heating curve is
normally within the range marked
A for underfloor heating systems,
B for modulating heating systems,
C for heating systems with boiler
water temperatures over 75°C /
167°F.
Slope
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
Outdoor temperature in °C
Examples
Well insulated house in protected
position (radiator heating):
Slope = 1.2
House in exposed position or with
old heating system (radiator
heating):
Slope = 1.6
Settings
21