Repair manual

24
4 / Troubleshooting
In the event of faults, start by checking…
• Defective wiring (short-circuits, open circuit).
• Visual inspection for
- corroded contacts
- defective fuses
- damaged electric lines, joints and connections
- damaged exhaust gas and combustion air piping
• Battery voltage on starting up the heater <19 V (measure
voltage on control unit).
• Check fuel supply.
• When changing over to Winter mode:
is summer diesel fuel still in the line?
• Delayed start-up --> nozzle holder heater switched on for
60 seconds.
• The Bus 2000 water pump and the HYDRONIC are
automatically switched off shortly after start-up if there is
insufficient coolant or the pump impeller is blocked.
Control unit locking
The control unit is locked if any of the following malfunctions
occurs:
• Overheating
If the HYDRONIC overheats 3x in succession - fault code
012, displayed as AF 015 ---> the control unit is locked.
• Flame during delayed shutoff
If the fault “Flame during delayed shutoff” is reported 3x
in succession - fault code 058, displayed as AF 016
---> the control unit is locked.
• Too many start attempts
After a sequence of ten unsuccessful attempts at starting
up the HYDRONIC - fault code 052, displayed as AF 050
---> the control unit is locked.
Release of control unit when locked
Release of the control unit following locking is described on
pages 26 to 29.
Test equipment
The following test equipment can be used for troubleshooting
and repair.
Cat. No.
• Diagnostic unit 22 1512 89 00 00
Additionally required:
adapter cable 22 1000 31 66 00
• SO adapter 22 1524 89 00 00
Additionally required
adapter cable 22 1000 31 66 00
• Test unit for burner head 22 1527 89 00 00