3 Function description Thermo 90 S / Thermo 90 ST
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3.6.2 Diagnosis after fault lock-out
Thermo 90 S and Thermo 90 ST
Check the fuses and plug connectors.
3.6.2.1 Version with digital timer
If the system is equipped with a standard clock, a fault
message appears on the display of the digital timer after
a fault occurs:
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 monitor interrupt or flame monitor short
circuit
F 06 Temperature sensor interrupt or temperature
sensor short circuit
F 07 Metering pump interrupt or metering pump short
circuit
F 08 Fan motor interrupt or fan motor short circuit or
fan motor incorrect speed
F 09 Glow plug interrupt or glow plug short circuit
F10 Overheating
F 11 Circulating pump interrupt or circulating pump
short circuit
3.6.2.2 Version with switch
If the system is operated with a switch, the nature of the
fault is indicated by a flashing code
on an operating
indicator light 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 Undervoltage or overvoltage
4x Premature flame recognition
5x Flame monitor interrupt or flame monitor short
circuit
6x Temperature sensor interrupt or temperature
sensor short circuit
7x Metering pump interrupt or metering pump short
circuit
8x Fan motor interrupt or fan motor short circuit or fan
motor incorrect speed
9x Glow plug interrupt or glow plug short circuit
10x Overheating
11x Circulating pump interrupt or circulating pump short
circuit
