Bosch GWI-N Series Training And Service Information page 73

Flame presence not
detected
Ensure P7 / P4-AP is
correctly defined
EC
Ionization failures during operation (loss of ionization 5 times in short period of time)
Characteristic:
Gas Valve / Ionization
Lock Out Error Burner shutdown / manual reset
Condition
Error code displayed
after start up
Note: the ionization is
lost in operation.
Error code displayed in
the unit recently
installed
(previously with other
kind of equipment's like
gas storage)
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Spark is ok and flame is
visible, but appliance shut off
and tries to re-ignite?
Ionization sensor
touching burner / metal
part?
Ionization cable is
disconnected /
damaged?
Incorrect adjustment in
speed of the fan for
minimum power (check
P0 / P2
Cause
Gas supply is not the correct or gas
dynamic pressure is not enough to
keep appliance working
Note: Lost of ionization current 5
times in less of 5 seconds.
Gas supply line is not adequate in
terms of size / diameter to the
installed power / system.
Incorrect wire connections to
ignition / ionization group
6 720 814 719 SM FP_Australia 2017/04 EN
Yes
Yes
Verify the correct assembly of
No
Verify and assure cable is
Yes
connected and in contact with
electrode (black wire). In case
of need replace wiring.
No
Flame is not a blue steady
Lean flame – decrease A2
value and increase L2
Solution
Check the gas type source and
correct gas supply problem.
Insufficient gas supply can cause
instable flame on the burner and
lack of ionization during operation
Check gas pressure measuring with
a gas manometer (digital or
manual) in the gas inlet measuring
point at the gas valve.
Verify the wire connections of the
ignition because Intermittent failure
and bad contact in terminals can
cause lack of ionization during
operation
electrode
one and is lifting?
Yes