BCU burner control unit
Fig. 71
PWM Control signal
X...
Electrical interfaces
§
A/B Flow temperature sensors 1 and 2
Outlet temperature sensor (gas condensing
$
combi boiler)
Ionisation electrode
aA
Flue gas temperature sensor
aG
sÖ
Internal circulation pump (primary circuit pump)
3-way diverter valve
dÖ
Gas solenoid valve
dG
B
Connection and wiring diagram
A
Power supply
fÖ
gF
Ignition unit
Fan motor
a-Ö
A Fan motor control
a-Ö
Water pressure sensor
aND
A DHW flow sensor
aND
BCU burner control unit
A
HMU heat management unit (plug
B
HMU heat management unit (plug X4)
C
C
)
aBH
123