Fig. 702 Combustion Chamber - Webasto Thermo Pro 90 Series Service Installations

Thermo Pro 90
7.6.2 Combustion chamber
Cover
Fig. 702 Combustion chamber
• The cover and the combustion chamber (Fig. 702) must
be firmly secured and have no play (check by lightly
moving). The burner unit must otherwise be replaced.
• The burner unit must be replaced if there is a radial gap
between the combustion chamber and cover.
• The fuel pipe must be firmly secured to the back plate
and must have no play (check by lightly moving the fuel
pipe).
Replace the burner unit if there is play between the fuel
pipe and back plate.
The combustion chamber (Fig. 702) should not be
damaged (e.g. dented). A dented combustion chamber
can cause poor combustion or coking of the heater. The
burner unit should be replaced in this case.
• The air holes (Fig. 702) in the burner unit should not be
clogged. Clogged air holes can result in the burner not
starting or poor combustion.
Carefully scrape the air holes clear.
• The metal fiber evaporator will not fit correctly if the
retainers (3x) are deformed or missing.
The burner unit should be replaced in this case.
Combustion chamber
Air holes
7.7 Restarting
Carefully bleed the coolant circuit and the fuel supply system
after installing the heater. Follow the vehicle manufacturer's
specifications. During the test run, check all coolant and fuel
connections for leaks and that they are firmly fitted. If the
heater encounters a fault during operation, perform the trou-
bleshooting procedure to locate the malfunction (see Section
5).
To assist the coolant circuit bleeding procedure, operate the
coolant pump with the "component test" function in
Webasto Thermo Test PC diagnostics.
ATTENTION
The coolant temperature must be < 60 °C before the heater
starts up otherwise burner operation may not take place. The
heater is to be placed into operation with Webasto Thermo
Test PC diagnostics. If completely empty, the fuel line should
be filled by means of Webasto Thermo Test PC diagnostics:
press the "Fill Line" button and pump fuel up to the heater.
During the heater test run, check all coolant and fuel connec-
tions for leaks and that they are firmly fitted.
7 Servicing
703