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11.2
Heating
The following paragraphs
describe the different functions of the boiler and their related “controlling behaviour settings”
as a central heating boiler.
11.2.1 C
ONTROLLING BEHAVIOUR SETTINGS
The factory settings for all heating applications are working fine and it is therefore advised not to change these
settings. If changes are needed always consult the manufacturer for advice.
P5 AO
Blocking offset flow temperature control (display A2).
The amount of degrees the measured temperature exceeds the active flow temperature set point before the heat
demand stops. Only active when the unit is controlled by the internal flow sensor (S1) and used for single unit control.
(not used!)
P5 AL
Hysteresis CH Flow temperature control (display A4).
The amount of degrees that the measured temperature must drop, relative to the active flow temperature set point +
Offset (Parameter P5 AO), before the heat demand starts. This function is active when the unit is controlled by the
internal flow sensor (S1) and used for single units. When controlling cascaded units with an external system sensor
(S3), this sensor will be used.
(not used!)
P5 AP
Proportional range single heating boiler (display A3).
The proportional range for controlling the flow temperature of the boiler. This function is active when the unit is
controlled by the internal flow sensor (S1) and used for single units. When controlling cascaded units with an external
system sensor (S3), this sensor will be used.
(not used!)
P2 MI
Blocking offset System CH temperature control (display A6).
The amount of degrees the measured temperature exceeds the active flow temperature set point before heat demand
stops. Only active when the unit is controlled by an external system sensor (S3).
The following graph shows the relation between the several parameters.
WHEN CONTROLLING ON INTERNAL
FLOW SENSOR
Settings:
P5 AO
Offset
= 5°C
P5 AP
Proportional band = 15°C
P5 AL
Hysteresis
= 10°C
Temp. set point
= 50°C
Burner starts at 45°C
Set point + Offset - Hysteresis = 50+5-10= 45°C
Burner stops at 55°C
Set point + Offset = 50 + 5 = 55°C
WHEN CONTROLLING ON EXTERNAL
FLOW SENSOR
Settings:
P2 MI
Offset
= 5°C
P5 AP
Proportional band = 15°C
P5 AL
Hysteresis
= 10°C
Temp. set point
= 70°C
Burner starts at 65°C
Set point + Offset - Hysteresis = 70+5-10= 65°C
Burner stops at 75°C
Set point + Offset = 70 + 5 = 75°C
Curve and values only for illustration purposes, programmed parameter values can deviate!
11.2.2 R
OOM THERMOSTAT ON
/
OFF
A room thermostat with a fixed set point and using an ON/OFF control can be connected to the boiler (connections
13-14). Changing the flow temperature set point and activation of a timer program can be done by this room
thermostat or by programming the boiler settings. See chapter 10.10
BOILER OFF
SET POINT
ALLOWED TO
MODULATE
OFFS
E
T
P
R
OPOR
T
ION
A
L
B
A
N
D
H
Y
S
T
E
R
E
S
IS
BOILER ON
SET POINT + OFFSET
