Faults That Are Not Shown On The Display - Bosch ZSB 30-2 Installation And Servicing Instructions

70 | Fault mode

17.3 Faults that are not shown on the display

Appliance faults
Combustion noise too loud; rumbling noises
Flow noises
Heat-up takes too long
Flue gas readings incorrect; CO levels too high
Ignition too harsh, poor
Set flow temperature (e.g. of the FW-100
controller) exceeded
Condensate in air box
DHW temperature is not reached (ZWB)
Heatronic is flashing (i.e. all keys, all display
segments, burner indicator etc. are flashing)
Set room temperature not reached
Table 28 Faults not shown on the display
6 720 644 143 (2010/09)
Remedy
B Plug in boiler coding card correctly; replace if required.
B Check gas type.
B Check gas supply pressure; adjust if required.
B Check flue gas system; clean or repair if required.
B Check gas/air ratio in the combustion air and flue gas;
replace gas valve if required.
B Set pump stages or pump characteristic maps correctly and
match to maximum output.
B Set pump mode correctly.
B Set pump stages or pump characteristic maps correctly and
match to maximum output.
B Set pump mode correctly.
B Check gas type.
B Check gas supply pressure; adjust if required.
B Check flue gas system; clean or repair if required.
B Check gas/air ratio in flue gas; replace gas valve if required.
B Check gas type.
B Check gas supply pressure; adjust if required.
B Check power supply.
B Check electrodes with lead; replace if required.
B Check flue gas system; clean or repair if required.
B Check gas/air ratio; replace gas valve if required.
B For natural gas: Check external gas flow limiter; replace if
required.
B Check burner; replace if required.
B Switch OFF automatic cycle block, i.e. set value to 0.
B Set the required cycle block, e.g. standard setting of 3
minutes.
B Insert diaphragm in the mixing facility as per installation
instructions; replace if required.
B Plug in boiler coding card correctly; replace if required.
B Check turbine; replace if required.
B Replace fuse Si 3 (24 V).
B De-areate the hydronic system.
B Check the thermostatic radiator valves
B Check the demand from the controller
B Complete air purge (service function 2.C).