Error Code Output - Webasto Air Top 3500 ST Workshop Manual

Air Top 3500/5000 ST
5.4

Error code output

If the heater is fitted with a combination timer, an error
code output will appear on the display of the timer after a
fault occurs.
Error Error (group)
code
F 00 Control unit error
F 01 No start
F 02 Flame failure
F 03 Undervoltage or overvoltage
F 04 Premature flame recognition
F 06 External temperature sensor break
or short circuit
The error code is output if the heater is fitted with a control
element after an error has occurred by the switch-on
indicator/error code indicator flashing. After 5 seconds of
fast flashing, the error code will be output by a sequence
of long flash pulses, the number of flashes is shown in the
table below (for example F04 – 4 long flash pulses).
Additional information during PC
diagnostic
01 Control unit error
81 EOL checksum error
11 Incorrectly coded control unit or
incorrect heater (fuel type) installed (the
heater will not work if this error occurs)
91 Neutrally coded or disabled control unit
(the heater will not work if this error occurs)
92 Maintain command failed (the heater
will not work if this error occurs)
18Customer bus defective
02 Even after the restart, no flame has
formed
82 No start in test
03 The flame has gone out during
operation and has not reformed after a
restart attempt
83 The flame has gone out during a
heating cycle more than FAZ times
(EEPROM)
84 The voltage was less than 10.5 V or
21 V for longer than 20 seconds
04 The voltage was more than 16 V or
32 V for longer than 6 seconds
05 The flame sensor recognised a flame
before combustion had started
14 Temperature sensor circuit short circuit
to earth
94 Temperature sensor circuit break or
short circuit to +Ub
Fig. 503 Troubleshooting (page 1 of 2)
5 Troubleshooting
NOTE
Remedy
Replace control unit
Check fuel supply (tank empty, lines
blocked)
Clean burner insert, replace flame sensor
Check fuel supply (tank empty, lines
blocked)
Clean burner insert, replace flame sensor
Replace flame sensor
Check cables, replace temperature sensor
Check cables and terminating resistor,
replace temperature sensor
503