Technical data

Air Top 2000 ST Troubleshooting
503
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.
NOTE
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).
Error
code
Error (group) Additional information during PC
diagnostic
Troubleshooting
F 00 Control unit error 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)
18 Customer bus defective
Replace control unit
F 01 No start 02 Even after the restart, no flame has
formed
82 No start in test
Check fuel supply (tank empty, lines
blocked) Clean burner insert,
Petrol:
Replace flame monitor
Diesel:
Replace overheating sensor / control unit
F 02 Flame failure 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)
Check fuel supply (tank empty, lines
blocked) Clean burner insert,
Petrol:
Replace flame monitor
Diesel:
Replace overheating sensor / control unit
F 03 Undervoltage or
overvoltage
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
Charge battery
F 04 Premature flame
recognition
05 A flame was detected before
combustion had started
Diesel: Replace overheating sensor /
control unit
Petrol: Replace flame monitor
Fig. 503 Troubleshooting