Description Of Various Steps; Calling Up The Latest Fault (Service Function 6.A); Fresh Water Filter (Only Combi Boiler Zwb; Plate Type Heat Exchanger (Only Combi Boiler Zwb - Bosch Greenstar Series Installation And Service Instructions For Contractors

Inspection and maintenance
15.1

Description of various steps

15.1.1 Calling up the latest fault (service function 6.A)

▶ Select service function 6A (page 60).
An overview of the faults can be found on page 74.
15.1.2 Fresh water filter (only combi boiler ZWB...-3A)
▶ Close cold water tap.
▶ Depressurize the cold water pipe.
▶ To access the filter remove the safety clip (step 1), pull out the pipe
(step 2), and remove the filter from the pipe (step 3).
▶ If necessary, clean with plastic brush under running water.
1
Fig. 83 Filter in fresh water pipe
15.1.3 Plate type heat exchanger
(only combi boiler ZWB...-3A)
If the DHW output on the combi boiler is significantly reduced:
▶ Check filter in the cold water pipe for contamination ( page 66).
▶ Depressurize the appliance.
▶ Remove plate type heat exchanger and replace
-or-
▶ Descale with descaling agent approved for stainless steel (Grade
316-1.4401).
To remove the plate type heat exchanger:
▶ Unplug electrical connections.
▶ Remove hose from safety relief valve.
Fig. 84 Unplugging electrical connections / removing hose from safety
relief valve
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2
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▶ Loosen/remove pipe connections.
Fig. 85 Removing pipe connections
▶ Remove the boiler pressure gauge from the Heatronic boiler control.
Fig. 86 Removing the boiler pressure gauge
▶ Loosen the quick releases (steps 1 and 2) and remove the hydraulic
assembly in its entirety (step 3).
2.
1.
Fig. 87 Removing the hydraulic assembly
▶ Remove the plate type heat exchanger.
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3.
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Greenstar – 6721822579 (2021/01)