Technical data

Thermo 90 S / Thermo 90 ST Troubleshooting
63
12 Troubleshooting
12.1. 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).
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 undervoltage guard switches off the system
for longer than 20 seconds, the fuel supply is interrupted.
12.2. Diagnostic after a fault lock-out
for the Thermo 90 S and Thermo 90 ST
Check the fuses and plug connectors.
12.2.1. Version with timer
If the system is equipped with a standard clock, a fault message appears
on the display of the timer after a fault occurs:
Thermo 90 S Thermo 90 ST
12 V 10.5V – 0.5V 10.5V – 0.5V
24 V 21V – 1V 21V – 1V
F 00 Heater lock-out or control unit defective,
Unlocking only possible by an authorised workshop
F 01 No start (after 2 attempts to start)
F 02 Flame failure
F 03 Undervoltage or overvoltage
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