Electrical Diagram; 2.10 Function - Bosch WR11B series Installation Manual And Operating Instructions

8 | Technical Characteristics and Dimensions
2.9

Electrical diagram

Fig. 3 Electrical diagram
1 Servo valve (normally open)
2 Diaphragm valve
3 Main valve (normally closed)
4 Ionisation detector
5 Igniter electrode
6 Flue gas safety device
7 Temperature limiter

2.10 Function

This gas heater is equipped with automatic electronic
ignition which simplifies its operation.
B To do so, just turn on the switch ( Fig. 6).
After this procedure, automatic ignition occurs
whenever a hot water tap is opened. First, the pilot
burner is lit and approximately four seconds afterwards
the main burner. The pilot burner flame is then
extinguished after a short period of time.
This is a way of saving a great amount of energy as the
pilot burner only operates for the minimum necessary
time to ignite the main burner, in contrast to
conventional systems which operate permanently.
6 720 648 592 (2011/06)
8 Igniter unit
9 LED indicator for battery charge level
10 LED indicator for burner status
11 ON/OFF switch
12 Batteries, 1.5V
13 Microswitch
Air in the gas supply pipe when the heater is
started up may cause ignition to fail.
If this happens:
B Close and open the hot water tap to repeat the
ignition process until all the air has been purged.