Combustion Air Fan; Fuel Pump; Heat Exchanger; Combustion Chamber - Webasto Thermo 230 Workshop Manual

2 General Description
2.1

Combustion Air Fan

The combustion air fan supplies the air required for com-
bustion from the combustion air inlet to the combustion
chamber.
Splash protection cover
Screen
The fan consists of a fan motor with fan wheel. Air is taken
in through a splash protection cover or a screen and the
cap.
2.2

Fuel Pump

For operation with PME (Bio Diesel) a special PME fuel
pump is installed.
The fuel pump delivers the fuel and is driven by the fan
motor via a clutch. The fuel is compressed in the pump to
approximately 10 bar and diffused by a high pressure
nozzle. A screwed on solenoid valve controls the fuel flow
to the nozzle.
Solenoid valve
Screen
O-ring
202
Fan motor
Fan wheel
Cap
NOTE
Nozzle block
preheater
Fuel pump
2.2.1 Nozzle block preheater
For operation with PME (Bio Diesel) the installation of a
nozzle block preheater is mandatory.
At extremely low temperatures malfunctions may occur
without a nozzle block preheater.
At a temperature of < 0 °C a thermostat activates the
heater cartridge in the nozzle block. The heating period
depends on the heat reflected within the combustion
chamber. Preheating is deactivated when the thermostat
ambient temperature is +8 °C.
If the heater is not equipped with a nozzle block preheater
a retrofit is possible.
2.3

Heat Exchanger

The heat exchanger transfers the heat generated by com-
bustion to the coolant circuit.
2.4

Combustion Chamber

The fuel/air mix is dispersed in the combustion chamber
for combustion to heat the heat exchanger.
Heat exchanger
Combustion chamber
Thermo 230 / 300 / 350
NOTE