Preheater Troubleshooting; Displaying Faults On The Timer; Heater Control Box Software Lock; Unlocking The Control Box And Deleting The Fault Memory - PREVOST H3-41 Maintenance Manual

8.4

PREHEATER TROUBLESHOOTING

Fault codes can be displayed through the
preheater timer which can display up to 5 fault
codes.
8.4.1

Displaying Faults On The Timer

Condition: The heater is switched off.
• Press button –>; the heater is switched on.
• Press button and keep it depressed, then
press button within 2 seconds.
The display is as follows:
AF = current fault
3 digit number = fault code
flashes.
• Press button once or several times, fault
memory positions F1 – F5 are displayed.
8.4.2

Heater Control Box Software Lock

The heater's control box can become locked if
certain conditions are encountered.
• Overheating
If the heater overheats 3x in succession – fault
code 012, is displayed as AF 015 –> the control
box is locked.
• Flame in after-run
If the fault "flame in after-run" is signaled 3x in
succession –fault code 058, is displayed as AF
016 –> the control box is locked.
• Too many attempted starts
If the heater carries out ten failed start attempts
in succession – fault code 052, is displayed as
AF 050 –> the control box is locked.
Consult the complete list of fault codes in the
Eberspacher Hydronic LII Troubleshooting and
Repair manual under 4 Troubleshooting / Fault
code table.
8.4.3 Unlocking The Control Box And
Deleting The Fault Memory
CAUTION
Unlocking the control box erases useful
troubleshooting information at the same time.
To unlock:
•On the timer located on the console left of the
driver, press button
SECTION 22: HEATING AND AIR CONDITIONING
The display is as follows: the current fault, e.g.
AF 015.
• Press button
press button
The module timer is now in the "Enquire fault
memory" program.
• Switch off ignition (terminal 15).
• Simultaneously press buttons
addition, switch on the ignition (terminal 15) and
wait until the following appears in the display
after ignition "ON":
Display " - - - -" flashes, heater symbol does not
flash.
• Switch the heater off and on –>; the control
box is unlocked, the heater restarts.
After switching the heater off and on and
renewed query of the fault memory, the following
appears in the display, confirming fault memory
is reset:
Display "AF 00" flashes, heater symbol does not
flash
8.5

PREHEATER MAINTENANCE

Before the cold season, a trial run should be
carried out for the heater.
Check air intake and exhaust to make sure there
is free air/exhaust flow and no obstruction.
If thick, persistent smoke develops, unusual
burning noises or a clear fuel smell occurs or if
electric / electronic parts overheat, the heater
must be switched off and put out of service by
removing the fuse. Refer to vehicle schematic.
The unit should not be started up again until it
has been checked by qualified staff.
Check the main components of the heater for
proper operation and adjustment.
Consult
Troubleshooting and Repair manual .
NOTE
If there are no preheater faults, the preheater
will go through a normal start cycle and
regulate based on thermostat setting.
NOTE
Switch on the preheating system for about 10
minutes about once a month, even during the
warm season.
PA1621 Maintenance Manual All Series | Revised February 2019
and keep it depressed, then
within 2 seconds.
Eberspacher Hydronic
the
and , in
LII
73