Spheros thermo 231, Workshop Manual

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Thermo 230 / 231 / 300 / 301 / 350 2 General Description
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2 General Description
The water heaters Spheros Thermo 230, 231, 300, 301
and 350 are used in combination with the vehicle’s own
heating installation to
– heat the passenger compartment
– defrost the windscreen
– preheat water-cooled engines
The heaters Thermo 231 and 301 are variants for vertical
installation. The difference in appearance are the different
identification label and the Z profiles on the installation in-
terface.
The water heater operates independent from the vehicle
engine and is connected to the vehicle cooling system,
the fuel system and the electrical system.
The heater designed to the heat exchanging principle
operates intermittently controlled by the temperature
sensor.
The heaters Thermo 230, 231, 300, 301 and 350 basically
consist of
– the combustion air fan
– the fuel pump with nozzle block and nozzle
– the heat exchanger and
– the combustion chamber
– the igniter box with igniter electrodes
For control and monitoring the heater includes
– a control unit
– a flame sensor
– a temperature sensor
– a temperature limiter
– a temperature limiter without reset button for Thermo
231 and 301 and the Rail variant .126.
An external circulating pump is installed inside the vehicle,
or, in the case of compact units, directly at the heater.
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6
7
8
9 10
1
2
4
3
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Thermo 231/301
Thermo 231/301
1 Burner
2 Coolant inlet
3 Temperature limiter
4 Temperature sensor
5 Coolant outlet
6 Heat exchanger
7 Exhaust outlet
8 Fuel return
9 Combustion air inlet
10 Fuel delivery
11 Splash protection cover
(instead of screen)