5 Troubleshooting Thermo 90
502
5.3 Failure Symptoms after Switch-off
upon Failure
NOTE
When operated with a switch the type of failure is
ind
icated by a flash code of the operation indicator light
during heater run-down.
After five short signals the long flash pulses are counted.
The heater Thermo 90 S with standard timer outputs
errors to
the timer display for indication (see 3.6.3).
The following table may also be used as representative
re
ference.
Fig. 502 Failure Symptoms after Switch-off upon Failure (Sheet 1 of 2)
Failure Symptom Failure Symptom Remedy
No function Electrical wiring,
fuses
Check fuses
Check battery connections
+ at A5 / – at A3 / + from A1
(Thermo 90)
+ at 12 / – at 9 / + at 3, connector X12
(T
hermo 90 S)
Control unit defective Replace control unit
1 Flash pulse
(no start)
Fuel system Check fuel level
Check fuel filter
Bleed fuel system
Combustion air/exhaust duct Check combustion air/exhaust duct for
f
oreign matter and clean as required
Burner Clean burner or replace as necessary
2 Flash pulses
(flame-out during operation)
Fuel supply Check fuel level
Check fuel filter
Bleed fuel system
Burner Clean burner or replace as necessary
3 Flash pulses
(low voltage)
Electrical power supply Check battery
Check electrical connections
4 Flash pulses
(flame sensor continuously
hot)
Flame sensor defective Replace flame sensor
5 Flash pulses
(flame sensor defective)
Wiring Check wiring for damage,
open connections or short circuit
Flame sensor defective Replace flame sensor
6 Flash pulses
(temperature sensor defective)
Wiring Check wiring for damage,
open connections or short circuit
Temperature sensor Replace temperature sensor
7 Flash pulses (dosing pump
d
efective / overheat protection
defective)
Coolant circuit Check coolant level
Bleed coolant circuit
Reset temperature limiter
Wiring Check wiring for damage,
open connections or short circuit
Dosing pump defective Replace dosing pump
To Next Page
Loading...
Need help?
General
