Bosch WTD 15-4 AME 23 - Page 25

Page 25 from 45 6 720 887 546 “SM FP_ErP LPP-MPP Europe 2018/05 en”
Overview of ECU (electronic control unit) LPP
1- Ionization electrode (Flame detection) 10- APS (air pressure switch)
2- Ignition electrode 11- Segment valve B
3- Transformer 12- Segment valve A
4- Power supply 13- Gas valve solenoid
5- Fan 14- Safety solenoid valve
6- Water flow sensor 15- Temperature limiter (thermostat)
7- Water inlet temperature sensor
8- Water outlet temperature sensor
9- HMI
Pict.32 – Electric Diagram LPP circuit board