48
17.0 Fault Finding
© Baxi Heating UK Ltd 2016
Refer to “Illustrated Wiring Diagram” for position of terminals and components
Central Heating -
Follow operational sequence
Turn on mains power
The display illuminates
20, 28, 40 or 321 flashing
117 or 118 flashing
09, 15, 110, 125, 133, 134,
135 or 384 flashing
Set Central Heating
temperature to Maximum.
symbol flashing, pump runs
Go to section ‘A’
Go to section ‘D’
Ensure all controls and
programmers are calling for
heat
Go to section ‘B’
If 110 is still flashing go to
section ‘H’
YES
YES
NO
NO
NO
YES
YES
YES
NO
YES
YES
YES
NO
NO
NO
Go to section ‘I’
Ensure controls are set to
demand and verify the
contacts are closed
NO
Press the reset button for 1 to
3 seconds
NO
Fan runs after up to 3 minutes
160 flashing
Go to section ‘C’
NO
If 09, 15, 110 or 384 is flashing or re-occurs
regularly, check all PCB connections. If this has no
effect replace the PCB.
Fan runs at correct speed
160 flashing
Go to section ‘C’
Spark at ignition electrodes up
to 5 seconds & for 3 attempts
Go to section ‘F’. Press the
reset button for 1 to 3 seconds
YES
Burner lights
Go to section ‘E’
Burner goes out after 5
seconds
133 flashing
Go to section ‘G’
YES
YES
NO
109 flashing
125 flashing after 1 min
Go to section ‘
J
’
YES
YES
110 flashing
NO
Go to section ‘H’
YES
NO
Diverter valve open to Central
Heating circuit
NO
Go to section ‘K’
YES
Burner modulates to maintain
set temperature
Check Heating flow sensor.
Go to section ‘D’
NO
130 flashing
NO
Go to section ‘M’
YES
Burner goes out
NO
Fan stops after 10 seconds
YES
Boiler operation correct
YES
133 flashing
