Bosch Therm C1050ES Technical Service Bulletin page 2

2 | Replacing The Control Unit
 Locate rating plate sticker on right side of heater cover.
Determine model number (Fig.1, pos.A) and gas type (Fig.1,
pos.B).
 Locate hot water outlet pipe (Fig.2, pos.A). Determine the type
of outlet temperature sensor installed on the hot water outlet
pipe (Fig.3).
Surface mount outlet
temperature sensor
Data subject to change without notice | Printed in the USA | BTC 740002317 C | 06.2012
PCB jumper installation

Figure 1

Figure 2
C 950 ES or 830 ES with surface mount outlet temperature
sensor
Figure 3
C 950 ES or 830 ES with immersed outlet temperature sensor
Immersed outlet
temperature sensor
In order for the appliance to work correctly, the proper jumpers
must be installed on the PCB board. (Fig.4)
Backside of control unit Backside of control unit
Based on your model, gas type and type of outlet temperature
sensor, jumpers should be installed on the PCB in the following
arrangement:
Natural Natural
Gas Gas
Natural
Gas
Technical Service Bulletin
Figure 4
Figure 5
Liquid
Propane
Figure 6
Liquid
Propane
NO
JUMPER
NEEDED
Bosch Thermotechnology Corp.