501
Thermo 230 / 231 / 300 / 301 / 350
5 Troubleshooting
5
Troubleshooting
5.1
General
This section describes troubleshooting procedures for the
heaters
Thermo 230, 231, 300, 301
and
350
.
ATTENTION:
Troubleshooting requires profound knowledge about
components of the heater and their theory of opera-
tion and may only be performed by trained personnel.
In case of doubt functional interrelations may be derived
from Sections 2 and 3.
ATTENTION:
Troubleshooting is normally limited to the isolation of
defective components.
The following possible causes for trouble have not
been taken into consideration and must always be ex-
cluded as a possible cause for malfunction:
corrosion on connector
loose contact on connector
wrong crimping on connector
corrosion on wiring and fuses
corrosion on battery terminals
After any fault correction a functional checkout in the
vehicle has to be performed.
5.2
General Fault Symptoms
The following table (
) lists possible fault
symptoms of general nature.
Error symptom
Possible cause
Error in the electrics
Operation indicator does not light and the heater does
not function.
•
No supply voltage.
•
Fuses.
•
Supply cable to the plug contacts of plug A of the
control unit.
Fuse F2 triggered.
Short circuit in the circulating pump or in the
supply cable to the heater.
Fuse F3 triggered.
Short circuit in the supply cable to the heater/ burner
motor/ nozzle block preheater (if installed).
Heater is functional, however the operation indicator
does not light.
Operation indicator defective or cables to
the operation indicator interrupted or shorted.
Error in the water system
Circulating pump not operating
(only U 4851 and Aquavent 6000SC only).
•
Failure mode activated
The failure mode switches the motor off in case of mal-
functions. After approx. 5 sec the failure mode switches
the motor to the power saving sleep mode.
In the sleep mode the internal consumers of the motor
electronics are switched off. The power consumption in
this mode then amounts to < 2 mA.
The motor can be reactivated out of the sleep mode by
disconnection of the power supply for approx. 2 minutes.
After power reconnection the motor will again run up with
a soft start.
Fig. 501 General Fault Symptoms (Sheet 1 of 3)
Summary of Contents for spheros thermo 230
Page 70: ...memos...
