Maintenance And Service; Diagnostic Mode - Bosch GWH 345 ESR-N Manual

5

Maintenance and service

Warning: Always turn off the electrical
power supply, turn off the manual gas
valve and turn off the manual water shut
off valves whenever servicing.
The unit should be checked once a year by a gas
technician. If repairs are needed, the repairs should be
done by a gas technician
To remove front cover
B Loosen the two Philips head screws (as shown in
Fig. 2).
B Pull control panel upwards and then pull it
downwards.
B Lift front cover panel upward and remove.
Yearly maintenance
Refer to diagrams on pages 37 and 38.
• Inspect venting system for leaks, blockage or other
damage
• Unclip 4 access clips and remove cover to inspect
and clean burner assembly
• Manual operation of the pressure relief valve to insure
correct operation
• If flow is reduced or error AA is activated, flush the
heat exchanger with a descaling solution if mineral
build up is evident. Scale build up will shorten the life
of the water heater and is not covered by warranty.
Descale heat exchanger thoroughly and repeat
annually depending on mineral content of ground
water.
5.1

Diagnostic mode

The Diagnostic Mode provides diagnostic information
to the technician with a variety of real time parameters.
See Table 16 for the parameters and their respective
meaning.
Accessing the Diagnostic mode
B Switch on the equipment.
B Press and hold the reset button
B Rotate the hot water temperature sensor dial
the minimum and to the maximum.
Now the appliance is in the Diagnostic Mode.
Selecting parameter
B Rotate the recirculating water temperature selector
(left dial) to scan the different parameters.
Rotating clockwise accesses the next parameter
(increasing).
Once the desired parameter number has been
selected, the digital display will change to the value
stored in that parameter.
6 720 607 909
Adjusting parameters
B Rotate hot water temperature selector dial
change the value of the parameter (only parameter
03 and 22).
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Maintenance and service
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31