System Types For Modulating Boilers - Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual

Heating system types
Heating system types for modulating boilers
System type 1 – Single-boiler system with shunt pump for raising the return temperature
in conjunction with
Vitorond 200, VD2
A1 M2
1
28
21
5
B
A Boiler with Vitotronic 300
B Domestic hot water tank
C Heating circuit with mixing valve
*1
On the Vitorond the boiler supply and return are at the rear of the boiler.
6
M3
T2
17B
17A
3
T1
A
plugs
! Outdoor temperature sensor
? M2 Supply temperature sensor,
mixing valve circuit 2
? M3 Supply temperature sensor,
mixing valve circuit 3
§ Boiler temperature sensor
DHW tank temperature sensor
%
aJA Temperature sensor T1
aJB Temperature sensor T2
sÖ A1 Close mixing valves with
external heating circuit controls
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
C
M2
2
20
52
*1
sA
sK
sL
fÖ
fA
gS M2 Mixing valve motor, mixing
gS M3 Mixing valve motor, mixing
lÖ
aVD
aVH
C
M3
2
20
52
DHW pump
DHW re-circulation pump
Shunt pump
Power supply connection,
120 VAC
Burner (1st stage)
valve circuit 2
valve circuit 3
Burner (2nd stage/modulating)
Connection of external
equipment (see page 38)
Connection of external
equipment (see page 39)