Troubleshooting - Webasto Thermo 90 ST B Installation Manual

Troubleshooting

14. Troubleshooting
14.1 General Information
The control unit continuously monitors the heater
operation. The control unit identifies errors on individual
heater components and faults during operation. Should
the control unit experience component errors and
operational faults, the heater will be shut down.
14.2 Fault Lock-out
Fuel is supplied for max. 240 seconds if the flame does
not start to burn.
Fuel is supplied for max. 240 seconds if the flame goes
out during operation.
The fuel supply is shut off if the system overheats
(temperature limiter is tripped). If the system overheats
the button on the temperature limiter must be reset.
Once the cause of the fault has been eliminated, the
fault lock-out is cancelled by switching the heater off and
on again.
If the under-voltage protection switches off the system
Thermo 90 ST
12 Volt 10.V – 0.5V
24 Volt 21V – 1V
for longer than 20 seconds, the fuel supply is interrupted.
Webasto Product N.A., Inc.
14.3 Diagnostic after a Fault Lock-out for
the Thermo 90 ST
Check the fuses and plug connectors.
14.3.1 Version with switch
If the system is operated with a switch, the nature of the
fault is indicated by a flashing code on an indicator light
(toggle of switch) during the run-on time of the heater.
After five short signals, count the long flashes:
1x No start (after 2 attempts to start)
2x Flame failure
3x Under-voltage or over-voltage
4x Premature flame recognition
5x Flame sensor interrupt or flame sensor short-circuit
6x Temperature sensor interrupt or temperature sensor
short-circuit
7x Metering pump interrupt or metering pump short-
circuit
8x Blower motor interrupt or blower motor short-
circuit or blower motor incorrect speed
9x Glow plug interrupt or glow plug short-circuit
10x Overheating
11x Circulating pump interrupt or circulating pump
short-circuit
14.3.2 Version with timer
If the system is equipped with a digital timer, a fault
message appears on the display of the timer after a fault
occurs:
F 01 No start (after 2 attempts to start)
F 02 Flame failure
F 03 Under-voltage or over-voltage
F 04 Premature flame recognition
F 05 Flame sensor interrupt or flame sensor short-
circuit
F 06 Temperature sensor interrupt or temperature
sensor short-circuit
F 07 Metering pump interrupt or metering pump
short-circuit
F 08 Blower motor interrupt or blower motor short-
circuit or blower motor incorrect speed
F 09 Glow plug interrupt or glow plug short-circuit
F 10 Overheating
F 11 Circulating pump interrupt or circulating pump
short-circuit
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Thermo 90 ST
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