Install Instructions

Inspection and maintenance | 69
6 720 806 992 (2013/09)Greenstar
Heat exchanger
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.
Notes on installation and operation
• The following analytical tools are needed for service and
maintenance:
– Electronic flue gas analyzer for CO
2
, O
2
, CO, and flue gas
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).
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.
Fig. 83 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. 84 Unplugging electrical connections / removing hose from safety
relief valve
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.
NOTICE: The Heatronic boiler control can be damaged
by leaking water.
▶ Cover the Heatronic prior to working on water filled
components.
An overview of the faults can be found on page 77.
An overview of the faults can be found on page 77.
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