Repair manual

31
Fault code Cause
Fault Description • Remedial measures
020 Ignition spark generator - open circuit Control line from ignition spark generator to the control unit has open circuit
or short circuit.
• Check cable section from the ignition spark generator to the control unit
and, if necessary, eliminate open circuit or short circuit.
• Check functioning of the ignition spark generator only with the test unit for
burner head; if necessary ,replace the ignition spark generator.
• If the fault could not be eliminated by taking the remedial measures listed
above, --> replace control unit.
021 Ignition spark generator - ground leakage Control line from the ignition spark generator to the control unit has ground
leakage.
• Check cable section from the ignition spark generator to the control unit
and, if necessary, eliminate ground leakage.
• Check functioning of the ignition spark generator only with the test unit for
burner head; if necessary, replace the ignition spark generator.
• If the fault could not be resolved by taking the remedial measures listed
above, --> replace control unit.
025 Diagnostic output - short circuit Blue / white 1 mm² cable from the 18-pin control unit connector,
compartment 12 to the 8-pin cable harness connector, compartment 2 has
short-circuit against +U
B
• Check lead and connections and, if necessary, eliminate short circuit.
032 Burner motor does not turn - on start-up Fan wheel is chafing or is blocked.
033 Burner motor does not turn - during operation Burner motor faulty.
Generator voltage too low.
• Check that fan wheel is running freely.
• Check lines and connections to the burner motor.
• Check functioning of the installed burner motor only with the test unit for
burner head; if necessary, replace the burner motor.
• If the fault could not be eliminated by taking the remedial measures listed
above, --> replace control unit.
Fuel pump is blocked.
• Check that fuel pump is running freely. If necessary, replace the burner.
037 Water pump - fault Check in advance:
• Is Bus 2000 water pump installed?
• Is Bus 2000 water pump cable section “Diagnosis” connected?
• Does the Bus 2000 water pump have any power?
If yes - detach plug connection from the “Diagnosis” cable section.
Start HYDRONIC - if fault code 037 is no longer displayed,
then check the Bus 2000 water pump for dry running
and / or for blockages.
- If fault code 037 continues to be displayed, then apply the
remedial measures described for the water pump (standard
model).
• Water pump (normal model) is installed?
If yes - detach plug connection from the “Water pump” cable section,
apply power to the 2-pin connector on the “Water pump”
cable section and check for correct functioning.
If the water pump is functioning OK, then check fuse (15A),
cable section and water pump connections --> if fault code
037 continues to be displayed, then replace the control unit.
High voltage
High voltage
Apply max. 12 V at burner
motor
4 / Troubleshooting