8. Servicing
8.1 General
This section describes the servicing procedures that
may be performed with the air heater installed.
8.2 Work on the Air Heater
Prior to performing any work it is mandatory to discon-
nect the vehicle battery main lead. As long as the air
heater is in operation or in run-down, the battery main
supply must not be disconnected due to the danger of
overheating resulting in a response of the overheat pro-
tection.
When performing extensive repairs on the heater a com-
plete removal is advisable. When performing repairs re-
quiring a relocation of the installation position, the
relevant installation instructions and the vehicle-specific
installation proposal have to be observed.
8.3 Work on the Vehicle
CAUTION
In the vicinity of the air heater a temperature of 85 °C
must not be exceeded under any circumstances (e.g.
during body paint work).
8.4 Air Heater Test Run
WARNING
The air heater must not be operated, not even with
timer, in enclosed areas like garages or workshops not
equipped with an exhaust venting facility.
CAUTION
Operation of the heater without the control unit cover is
not permitted and causes overheating.
8.5 Servicing
NOTE
In order to avoid the seizure of mechanical components,
the air heater should be operated every 4 weeks for at
least 20 minutes.
The air heater does not require maintenance. It should
however be checked by Webasto-trained skilled person-
nel on regular intervals, the latest before the heating
season begins (point of time, when the heater is more
frequently in use due to weather conditions).
For reasons of the air heater’s functional reliability per-
form the following servicing:
check heating air inlet and outlet for foreign matter
and contamination. (Contaminated or clogged heat-
ing air ducts may lead to overheating and thus
response of the temperature limiter).
Clean air heater exterior (prevent the ingress of
water).
Examine electrical connections for corrosion of con-
tacts and for security.
Check combustion air and exhaust ducts for damage
and obstructions.
Check fuel lines and fuel filter for leakage.
Replace fuel filter if installed.
8.6 Visual Inspections and Installation
Regulations
8.6.1 Heating Air System
CAUTION
The integration of the air heater into the vehicle’s own air
system is not permitted due to the system’s high press-
ure and temperature.
Fitted in the air heater on the heating air intake side is a
temperature sensor, which operates the heater in the
relevant range of performance in conjunction with the
control dial dependent on the air intake temperature
and position of the rated value transmitter. Heating per-
formance is selected so that after quickly reaching the
preselected indoor temperature it is maintained at this
value. Air Top 2000 S heaters may be operated with an
external temperature sensor (see 9.1.2).
Minimum inside diameter of the heating air duct is
55 mm. Standard diameter is 60 mm.
NOTE
For heating air ducting only materials may be used
which are temperature-proof to at least 130 °C.
Maximum loss of pressure between suction and delivery
side of the heating air duct 1.0 mbar (10 mm water
column).
When exceeding this value the temperature limiter is
very likely to respond. The heating air hose is to be se-
cured at its joints.
801
Air Top 2000 S
8 Servicing
