Heating system types
11
Heating system types for modulating boilers
(continued)
Possible applications
Heating systems with distributor
arranged close to the boiler. The boiler
water flow is required to be reduced.
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T2 switches
on the shunt pump. If, as a result,
the required minimum return
temperature is not reached, the
return valve is proportionally closed
via the temperature sensor T1 and
the minimum return temperature is
assured.
The shunt pump must be sized so that
bypassed water accounts for approx.
30% of the total flow rate of the
boiler.
Available system accessories
Vitotrol remote control
Flue gas temperature sensor
Coding
system type
Change required
Automatic change
00: 1
If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1
Set coding ”02: 2” for operation with
modulating burner
––
03: 0
Set coding ”03: 1” for oil-fired operation
(re-setting is not possible)
––
0C: 0
Set coding ”0C: 1” for continuous return
temperature control
––
4A: 0
––
Connection of the temperature sensor T1 at
plug
aJ
A
;
Coding ”4A: 1” is set automatically
4b: 0
––
Connection of the temperature sensor T2 at
plug
aJ
B
;
Coding ”4b: 1” is set automatically
5285
941
-
0
1
