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 ZBR16-3A Series Installation And Service Instructions Manual

Heat exchanger
NOTICE: Damage to the coating of the heat exchanger.
▶ Cleaning of the heat exchanger should not be
necessary until five years after the initial
commissioning.
▶ Only use a Bosch cleaning blade or Bosch cleaning
brush ( page 98).
▶ Only clean heat exchanger if soiling is clearly visible.
Heatronic boiler control
In case of a component defect, a fault is shown on the display.
The Heatronic boiler control monitors all safety and control
components.
NOTICE: The Heatronic boiler control can be damaged
by leaking water.
▶ Cover the Heatronic prior to working on water filled
components.
Notes on installation and operation
An overview of the faults can be found on page 77.
• The following analytical tools are needed for service and
maintenance:
– Electronic flue gas analyzer for CO
temperature
– Pressure gauge 0 to 12 inches W.C. (0 to 30 mbar)
– pH Test strips
– Glycol tester of antifreeze is being used
• Special tools are not required.
• Approved lubricants are:
– For parts touched by water: Unisilkon L 641
(part-# 8 709 918 413 0)
– or fittings: HFt 1 v 5 (part-# 8 709 918 010 0).
▶ Use part-# 8 719 918 658 0 as heat conducting paste.
▶ Use only genuine Bosch spare parts.
▶ Request spare parts ( Section 19, page 83).
▶ Replace removed gaskets and O-rings with new ones.
After the inspection/maintenance
▶ Re-tighten all loosened threaded connections.
▶ Restart the appliance ( page 51).
▶ Check all connections for leaks.
▶ Check the gas-air ratio and adjust if necessary ( page 66).

15.1 Description of various steps

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

▶ Select service function 6.A ( page 62).
An overview of the faults can be found on page 77.
Greenstar
, O , CO, and flue gas
2 2
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. 84 Filter in fresh water pipe
(combi boiler ZWB..-3A only)
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 ( Fig. 69).
▶ 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. 85 Unplugging electrical connections / removing hose from safety
relief valve
Inspection and maintenance | 69
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6 720 641 933-92.1o
6 720 641 933-46.2O
6 720 806 992 (2015/03)