Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual page 8

Heating system types
Circuit Diagram 1
Single-boiler system with Therm-Control and three-way mixing valve
in conjunction with Vitorond 200, VD2A
A Heating circuit with mixing valves
B DHW tank
Plug
Outdoor temperature sensor
!
Flow temperature sensor,
?M2
mixing valve
?M3 Flow temperature sensor,
mixing valve
Boiler water temperature
§
sensor
DHW tank temperature sensor
%
aJA Therm-Control temperature
sensor
8
Heating circuit pump, mixing
sÖM2
valve
Heating circuit pump, mixing
sÖM3
valve
sÖA1 Closing the mixing valves with
external heating circuit control
units
DHW primary pump
sA
sK DHW circulation pump
fÖ Power supply, 120 VAC
60 Hz
Install the main isolator in
accordance with regulations
fA Burner (stage 1)
gSM2 Mixing valve motor
Mixing valve motor
gSM3
Burner
lÖ
(burner stage 2 / mod.)
aVD/aVH External connections
Please refer to the control
manual Vitocontrol-S,
VD2/CT3.