Actions In Event Of Faults; Heater Unit Cuts Out Automatically; Heater Unit Emits Black Smoke - Webasto Air Top Evo 3900 Operating Instructions Manual

Actions in event of faults

If an error occurs, first check the fuse and plug connections to ensure that they are in
proper condition and connected correctly.
If the actions described below do not rectify the error, have the heater checked by
Webasto-trained personnel.

Heater unit cuts out automatically

Cause
No combustion after
start and repeat start
Flame extinguishes during
operation
Heater unit overheats and
indicator flashes
Vehicle voltage too low

Heater unit emits black smoke

Cause
Combustion air and/or exhaust
system blocked
NOTE for ADR mode only:
After an ADR cut-out or the application of operating voltage by switching on the
main vehicle switch and setting the control element to "ON" the control unit will be
set to the "Fault cut-out" position.
Before the heater can be restarted the control element must be set to "OFF" or the
immediate heat button on the combination or standard timer must be pressed.
Remedy
Switch heater unit off (for at least 2 seconds) and then
on again
Switch heater unit off (for at least 2 seconds) and then
on again
Make sure that hot air can flow freely,
allow heater unit to cool down,
Switch heater unit off (for at least 2 seconds) and then
on again
Charge battery
Switch heater unit off (for at least 2 seconds) and then
on again
Remedy
Check combustion air and exhaust system for
blockage