Bosch Condens 8300i W - 10.1.3 Faults that Are Not Displayed

Troubleshooting
55
Condens 8300i W – 6721841531 (2022/10)
10.1.3 Faults that are not displayed
Table 29 Faults that are not shown on the display
Fault display: System pressure too low
If the system pressure in the heating system falls below the minimum
pressure that has been set, the display shows the message LoPr => L0.X
bar. The system pressure is too low.
▶ Fill the heating system.
If the system pressure in the heating system drops below 0.3 bar, the
display shows the message LoPr alternating with the operating
pressure. The heating system is then blocked.
▶ Fill the heating system.
Appliance faults Remedy
Combustion noise too loud; rumbling noises ▶ Check gas type.
▶ Check gas supply pressure.
▶ Check the flue system, clean or repair if required.
▶ Check the gas/air ratio.
▶ Check the air/gas ratio control valve, replace if required.
Flow noises ▶ Set the pump rate or pump characteristic map correctly and match to the maximum
output.
Heat-up lasts too long. ▶ Set the pump rate or pump characteristic map correctly and match to the maximum
output.
Flue gas readings incorrect; CO content too high. ▶Check gas type.
▶ Check gas supply pressure.
▶ Check the flue system, clean or repair if required.
▶ Check the gas/air ratio.
▶ Check the air/gas ratio control valve, replace if required.
Ignition too strong, or poor. ▶ Check the ignition transformer with service function t01 for misfiring, replace if
necessary.
▶Check gas type.
▶ Check gas supply pressure.
▶ Check the power supply.
▶ Check the electrodes with cable, replace if required.
▶ Check the flue system, clean or repair if required.
▶ Check the gas/air ratio.
▶ For natural gas: check external gas flow monitor, replace if required.
▶ Check burner. Replace if required.
▶ Check the air/gas ratio control valve, replace if required.
Condensate in the air box ▶ Check non-return valve in the mixing device, replace if necessary.
DHW outlet temperature not reached. ▶ Check turbine. Replace if required.
▶ Check the gas/air ratio.
▶ Check the heating system pressure and adjust if necessary.
DHW volume not reached. ▶ Check the plate heat exchanger.
▶ Check the heating system pressure and adjust if necessary.
No function, the display remains dark. ▶ Check electrical wiring for damage.
▶ Replace faulty cables.
▶ Check the fuse, replace if required.