Bosch GWI-N Series Training And Service Information page 75

F7
Ionization detected with appliance in standby
Characteristic: Ionization system
Lock Out Error
Loose or bad connection
between cable and
electrode
F9
Safety solenoid valve disconnected
Characteristic: electro valve
Lock Out Error
Loose connection in
safety solenoid (SV1 /
SV2 / SV3)
FA
Gas leakage error due to failure in gas valve that is not closing properly
Characteristic: Gas Valve + Ionization system
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Burner shutdown
Assure black wire is
securely connected to
the set of electrode
Ionization cable
damaged / defective
isolation ?
No
Ionization electrode
damaged?
No
Replace control unit
Burner shutdown
Verify wires connection:
SV1 – blue wires
SV2 – white wires
SV3 – black wires
Replace gas valve
6 720 814 719 SM FP_Australia 2017/04 EN
Replace wiring and
Yes
assure connection in
electrode
Yes
Replace electrode
Measure resistance of
SV ≈ 99.7 Ω
No
Problem solved?