General - Webasto Air Top Evo 3900 Workshop Manual

Air Top Evo 3900/5500
8 Servicing work
8.1

General

This section describes the servicing work that can be
carried out on the heater when it is installed.
8.2 Work on the heater
Disconnect the main power cable from the vehicle's
battery before carrying out any work on the heater.The
main battery power must not be disconnected whilst the
heater is operating or slowing down as a result of the risk
of the heater overheating and the overheating guard thus
being tripped. If you wish to carry out extensive repair
work on the heater, it may be a good idea to remove it
completely.
Refer to the relevant installation instructions and the
installation proposal for the heater for the specific vehicle
for repairs that necessitate the installation position being
changed.
8.3 Work on the vehicle
IMPORTANT
A temperature of 85 °C must not be exceeded in the
vicinity of the heater in any circumstances (for example
when competing painting work on the vehicle).
8.4 Heater trial
WARNING
The heater must not be operated in enclosed areas such
as garages and workshops without an emissions
extraction system, even if you use the timer.
IMPORTANT
The heater must not be operated without the cover for the
control unit as this will cause it to overheat.
8.5 Servicing work
To prevent mechanical parts seizing, the heater should be
operated for approx. 10 minutes every four weeks.
The heater requires no servicing.However, it should be
checked at regular intervals, at the latest at start of the
heating period (the time after which the heater will be used
due to adverse weather conditions) by Webasto-trained
personnel.
NOTE
After 3,000 operating hours a flash code (flashing pulses
at one-second intervals) are output with the operation
indicator. This code indicates the need for maintenance/
servicing of the heater to the user. The service signal is
output for 10 seconds during each heater unit start-up and
can be reset with the Webasto diagnosis by pulling the
fuse or with "Delete fault".
The following servicing work is to be carried out to
maintain the functional reliability of the heater:
• Check the hot air inlet and outlet for dirt and foreign
bodies. (Dirty or blocked hot air lines may cause
overheating.)
• Clean the exterior of the heater (avoid the ingress of
water).
• Check the electrical connections for contact corrosion
and to ensure that they are secure.
• Check the exhaust and combustion air lines for signs
of damage and to ensure that they are clear.
• Replace the fuel filter if there is one.
• Check the fuel line and filter for leaks.
8.6 Visual inspections and installation
instructions
8.6.1 Hot air system
IMPORTANT
The integration of the heater into the vehicle's own air
system is not permitted as a result of the high pressure in
the vehicle's system.
Inside the control unit there is a temperature sensor,
which operates the heater in the appropriate heat output
range in conjunction with the control element depending
on the intake temperatures and the position of the setpoint
generator. The heat output is set so that after the selected
interior temperature has been reached quickly, it is then
kept at this selected value.
Alternatively the Air Top Evo 3900/5500 heaters can be
operated with an external temperature sensor (see 9.1.2).
Only materials that can permanently withstand
temperatures of at least 130 °C may be used for the hot
air line.
Maximum pressure drop between the inlet and outlet side
of the hot air line:
Air Top Evo 3900
Air Top Evo 5500
1 hPa corresponds to 1 mbar corresponds to 10 mm H
(water column).
8 Servicing work
NOTE
2.0 hPa
3.0 hPa
O
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