Visual Inspections And Regulations For Installation; Connection To Vehicle Cooling System; Connection To Vehicle Fuel System; Fuel Lines - Webasto Thermo 230 Workshop Manual

8 Servicing
8.6 Visual Inspections and Regulations
for Installation

8.6.1 Connection to Vehicle Cooling System

The installation of the heater should be in a location as low
as possible to ensure self-venting of the heater and circu-
lation pump. This applies in particular for the circulation
pump because it is not self-sucking.
The heater is to be connected to the vehicle cooling
system according to Fig. 802. The cooling system coolant
capacity must be at least 10 liters.
The vehicle cooling system or the separate heating circuit
must use only pressure relief valves with an opening
pressure of at least 0.4 bar and of max. 2.0 bar.
It is a basic requirement to use the coolant hoses supplied
by Webasto, otherwise the hoses must at least meet the
specifications of DIN 73411. The hoses have to be instal-
led free of kinks and for proper venting in an inclination.
Hose connections must be secured against slippage with
hose clamps.
Hose clamps must be torqued with 1.5 Nm.
Prior to the heater's first operation or after replacement of
the coolant, attention must be paid to carefully bleed the
cooling system. Heater and lines must be installed so that
static venting is guaranteed.
Improper venting may cause malfunctions by overheating
in equipment operation.
Proper venting may be identified by a circulation pump
almost noiseless in operation.
When using a circulation pump U 4851 the circulation
pump automatically switches off approx. 15 seconds after
switch-on should coolant be missing or the pump wheel
be seized. After 2 minutes be pump may be reactivated.
In combination with control unit 1572D (Thermo label
colored) and with programmed circulation pump check the
heater also switches off when coolant is missing.
804
NOTE

8.6.2 Connection to Vehicle Fuel System

Fuel is tapped from the fuel reservoir of the vehicle or from
a separate fuel tank.

8.6.2.1 Fuel Lines

In order to avoid air from being captured in fuel lines, they
should only be installed with an incline. The fuel line joints
are to be secured against slipping with hose clamps
should no screwed mechanical unions be in use.
Should fuel hoses be installed always use the hoses
supplied or offered by Webasto. If other hoses are used
they must at least meet the specifications of DIN 73379.
Fuel hoses must not be kinked or twisted and must be
secured with clamps every 25 cm.
For routing fuel also fuel lines may be used consisting of
materials standard in the manufacturing of vehicles, e.g.
steel, copper or plastic lines made of unhardened, light
and temperature stabilized PA11 or PA12 (e.g. Mecanyl
RWTL) according to DIN 73378 observing the applicable
jointing instructions.
CAUTION
Heaters cleared or modified for the consumption of PME
(Bio Diesel) (observe identification label) and where PME
is used, it must be ensured that the fuel lines are PME
resistant.
Basic rules for the routing of fuel lines are:
• Protect against undue temperatures.
WARNING
In overheat condition the heater outer shell may reach
Diesel fuel inflammation temperature!
• Protect lines from stone strike.
• Dripping or evaporating fuel may neither accumu-
late nor ignite on hot components or electrical
equipment.
Thermo 230 / 300 / 350