Webasto Air Top 2000 STC Air Heater Fault Codes

This guide will assist you in identifying the cause of a fault, should one occur in the Webasto Air Top 2000 STC Air Heater fitted to your CamperKing campervan

Fault Code	Fault Message	Fault Details	Recommended Measures
00	No error	No error	No action necessary
01	Defective control unit	Defective control unit, wrong end-of-line programming or coolant temperature sensor (at water heaters) failure	Replace control unit
02	No start	After start-up has been repeated, combustion still fails to occur	1) Check for faults in the air intake and exhaust systems 2) Check for faults in fuel system 3) Check the fuel pump 4) Electrical check of glow plug
03	Flame failure	The flame went out during operation and combustion	See error 02
04	Supply Voltage too high	The supply voltage was too long above the maximum threshold value	Check system voltage
05	The flame was detected prior to combustion	Flame detector signals flame before combustion operation	1) Check for fault in the air intake, exhaust systems 2) Check for faults in the fuel system 3) Check the fuel pump 4) Electrical check of glow plug
06	Heating unit overheated	Overheat protection has been activated or the temperature at the the heat exchanger has exceeded the upper limit	1) Check for fault in air intake/blowout side, exhaust systems 2) Check for faults in the fuel system
07	Heater lock-out	Heater interlocked	1) Reset heater lock-out and attempt restart 2) Read out further fault messages and work through instructions Reset heater lock-out: switch on the heater. Pull fuse F1 for at least 10 s. Switch off the heater. Reinsert fuse F1. Switch on the heater. NOTE The following fault occurred several times: Fault counter: > 10x False start counter: > 7x Overheating counter: > 20x
08	Fuel pump short circuit	The fuel pump has a short circuit to ground	Electrical check of fuel system
09	Combustion air fan short circuit	The combustion air fan has short circuit to ground	Electrical check of combustion air fan motor
11	Wrong fuel coding	Incorrect parameter block or wrong heater (diesel/gasoline) used	Replace control unit
12	W-bus communication failure	W-bus communication failure	1) Check for fault in area of W-bus communication/W-bus control element/W-bus Telestart 2) Replace control unit
14	Temperature sensor short circuit (internal, external)	The temperature sensor has short circuit to ground	Electrical check of external/internal temperature sensor
15	Combustion air fan blocked	Combustion air fan blocked	1) Check for fault in fan motor 2) Heating air intake fan wheel snagging or jammed 3) Combustion air intake fan wheel snagging or jammed
17	Gradient exceedance overheat protection	The temperature rise at the heat exchanger has exceeded the upper limit.	Check for fault in air intake/blowout side, exhaust systems
18	Communication failure on customer-specific bus	Communication failure on customer specific bus	-
19	Glow plug/flame monitor short circuit	Glow plug / electronic ignition unit has a short circuit to ground	Electrical check of glow plug
81	EOL checksum error	The checksum of EOL dataset is wrong	Replace control unit
82	No start during test-run	No start during test-run	See error 02
83	Flame failure	Flame interruption during combustion operation, more than FAZ (EEPROM) times.	See error 02
84	Operating voltage too low	The supply voltage was too long below maximum threshold value	Check system voltage
88	Fuel pump interruption	Fuel pump interrupted or short circuit to supply voltage UB	Electrical check of fuel system
89	Combustion air fan interruption	Combustion air fan interrupted or short circuit to supply voltage UB	Electrical check of fan motor
91	Wrong control unit coding	Control unit locked or coded as neutral	Replace control unit
92	Command refresh failure	Command refresh failure	Check for fault in the area of W-bus communication/W-bus control element/W-bus Telestart
94	Temperature sensor interruption (internal, external)	Temperature sensor interrupted or short circuit to supply voltage UB	Electrical check of external/internal temperature sensor
97	Gradient undershooting during start	Overheat sensor position wrong (temperature gradient too low)	1) Check position of overheating sensor 2) Check fuel supply system
99	Glow plug / electronic ignition unit interruption	Glow plug / electronic ignition unit interrupted or short circuit to supply voltage UB	Electrical check of glow plug
0 A	Glow plug/flame monitor short circuit	Glow plug/Flame monitor circuit has a short circuit to ground	Electrical check of glow plug
1 A	Flame sensor short circuit	The flame sensor has a short circuit to ground	Electrical check of flame monitor
1B	Overheat sensor short circuit	The overheat sensor has a short circuit to ground	Electrical check of overheating sensor
8 A	Glow plug / electronic ignition unit interruption	Glow plug/Flame monitor interrupted or short circuit to supply voltage UB	Electrical check of glow plug
9 A	Flame sensor interruption	Flame sensor interrupted or short circuit to supply voltage UB	Electrical check of flame monitor
9B	Setpoint potentiometer interruption	Setpoint potentiometer interrupted or short circuit to supply voltage UB	Electrical check of setpoint sensor
AB	Overheat sensor interruption	Overheat sensor interrupted or short circuit to supply voltage UB	Electrical check of overheating sensor
F00	Defective control unit	Control unit defective EOL programming error	1) Check for fault in area of the W-bus communication/W-bus control element/W-bus Telestart 2) Replace the control unit
F01	No start	No flame formed even after a repeated start attempt	1) Check for faults in air intake and exhaust systems 2) Check for faults in fuel system 3) Check the fuel pump 4) Electrical check of glow plug
F02	Flame failure	The flame goes out during operation and no longer reformed after a restart attempt.	See error 01
F03	Supply Voltage too high	The operating voltage was higher than the maximum permissible value for too long	Check system voltage
F04	The flame was detected prior to combustion	The flame monitor detected a flame before combustion started	1) Check for fault in air intake, exhaust systems 2) Check for fault in fuel system 3) Check fuel pump 4) Electrical check of glow plug
F05	Flame sensor interruption	There is a break or short to UB in the electrical circuit of the flame detector	Electrical check of flame monitor
F06	Temperature sensor interruption (internal, external)	There is a break or short to UB in the temperature sensor	Electrical check of external/internal temperature sensor
F07	Fuel pump interruption	There is a break or short to UB in the electrical circuit of the fuel pump	Electrical check of fuel system
F08	Combustion air fan short circuit	The combustion air fan has a short to the ground or the fan motor is overloaded	Electrical check of combustion air fan motor
F08	Combustion air fan blocked	Combustion air fan blocking guard has tripped	1) Check for fault in fan motor 2) Heating air intake fan wheel snagging or jammed 3) Combustion air intake fan wheel snagging or jammed
F09	Glow plug / electronic ignition unit interruption	There is a break or short to UB in the glow plug/ignition spark generator	Electrical check of glow plug
F10	Heating unit overheated	Overheating lock-out has tripped (heater overheated)	1) Check for fault in air intake/blowout side, exhaust systems 2) Check for fault in fuel system
F11	Overheat sensor interruption	There is a break or short to UB in the electrical circuit of the overheating sensor	Electrical check of overheating sensor
F12	Heater lock-out	Heater lock-out was activated	1) Reset heater lock-out and attempt restart 2) Read out further fault messages and work through instructions Reset heater lock-out: switch on heater. Pull fuse F1 for at least 10 s. Switch off heater. Reinsert fuse F1. Switch on the heater. NOTE The following fault occurred several times: Fault counter: > 10x False start counter: > 7x Overheating counter: > 20x
F14	Gradient undershooting during start	Wrong position of overheating sensor (overheating sensor gradient too small)	1) Check the position of overheating sensor 2) Check the fuel supply system
F15	Setpoint potentiometer interruption	There is a break or short to UB in the electrical circuit of the setpoint potentiometer	Electrical check of setpoint sensor