Failure / Error Codes Overview - Bosch Condens 2000 W Service Manual

3.2

Failure / Error Codes Overview

Failure Code
on Display Failure Descripton
MAP not selected (Fan speed adjustment accord-
ing the flue pipe length).
A2 Combustion chamber NTC failure (behind burner) :
when the temperature by CC NTC reached to limit
1)
A6 Combustion chamber NTC failure (behind burner) :
when NTC not detected or open circuit
A7 Domestic hot water temperature sensor not correct
installed or failure.
2)
B3 --> d5 Short circuit / failure in water level switch.
3)
CE --> d4 Gradient limit : Temperature rises too rapidly in
heating mode.
C7 Fan sensor not detected.
C8 Fan speed can not reached to target speed.
d7 Modulator coil failure (regulator valve on gas valve) Check the cable connection.
EA Ignition lock-out (flame not detected) (pump is run-
ning).
E2 Flow temperature sensor failure (pump is running). Check the flow temperature sensor and the connection.
E9 Overheat lock-out by temperatur limiters (STBs)
(Flue gas + prim. Heatexchanger). In this case ;
Heat demands is blocked and pump stops 3 min.
later.
FA Safety valve leaks.
Tab. 3 Failure codes
1) Failure codes is adapted to the EMS (>FD660)
2) Failure codes is adapted to the EMS (>FD660)
3) Failure codes is adapted to the EMS (>FD660)
Steps
Check the adjustment /selection via service function
2.b.d).
Check the and the heat exchanger surface, whether is
blocked or not. And check the sensor and the connec-
tions.
Check the and the heat exchanger surface, whether is
blocked or not. And check the sensor and the connec-
tions.
Check the sensor and cable connection.
Check the condensate water drain and recuperator
(condens-heatexchanger).
Check the pump, system pressure and by-pass circuit.
Check the fan.
Check the fan for the blockage and the electrical supply.
Check the gas cock, gas pressure, electrode and the
cable connection.
Check the system presseure, temperature sensor, pump
and fuses on board. Discharge the air in system. Check
also the flue gas pipe and heatexchanger.
Check the gas valve, the cable connection and electrode
set.
Failures / Errors | 7