Webasto Thermo 230 Workshop Manual - page 45
8 Servicing
Thermo 230 / 300 / 350
808
8.7.6 Flame Sensor, Replacement
NOTE
The replacement procedure for the flame sensor is identi-
cal with the heater installed or removed.
Perform replacement in accordance with 9.2.8.
WARNING
The igniter box operates on high voltage. Prior to replace-
ment of flame sensor disconnect electrical connectors of
cable harness in vehicle to avoid lethal accidents.
8.7.7 Combustion Chamber, Replacement
NOTE
The replacement procedure for the combustion chamber
is identical with the heater installed or removed.
Perform replacement in accordance with 9.2.10.
WARNING
The heater operates on high voltage. Prior to replacement
of combustion chamber disconnect electrical connectors
of cable harness in vehicle to avoid lethal accidents.
8.8
First Operation
After heater installation the coolant circuit and the fuel
supply system must be thoroughly bled observing the
vehicle manufacturer’s instructions. During test runs all
coolant and fuel line connections have to be checked for
security and no leakage. Should the heater in operation
enter a fault condition, perform troubleshooting (refer to
Section 5).
NOTE
Heaters with control unit 1572D:
If the heater performs 5 subsequent attempts to start due
to a malfunction, the heater enters an error lockout and
stops any further attempts to start. This error lockout is
superior to the normal error lockout condition.
The error lockout reset is achieved by switching the heater
on and disconnection of the heater power supply within
120 sec. during run-down.
8.8.1 Water Circuit, Bleeding
NOTE
Bleeding must always be performed in accordance with
manufacturer’s instructions. For bleeding the circulation
pump must not be switched on.
Set vehicle own heating system to "warm" and replenish
coolant which must consist of at least 10 % anti-freeze
(on glycol base) (protection against corrosion). When
using pure water there will be no protection against
corrosion and due to the lower boiling point of the water
when overheating loss of cooling water may result
requiring continuous replenishment. Additives in the
coolant must not affect metals, plastics or rubber and
leave no deposits.
Then operate engine at increased idle until radiator
thermostat opens. Shut down engine, check coolant level
and replenish as required.
Switch on heater and vehicle heating fan with engine shut
down. After a certain cool-down period the heater must
automatically switch on and control to off. In case of no
restart attempt the temperature limiter on the heater has
responded because the heater has not been bled proper-
ly. Reset temperature limiter (push button on temperature
limiter) and repeat complete bleeding procedure.
NOTE
The heater may be equipped with an automatically
resetting temperature limiter. The manual reset is not
necessary.
8.8.2 Fuel Supply System, Bleeding
When switching the heater on the fuel pump sucks fuel to
prime the complete fuel supply system.
Should no combustion be achieved with the first start
attempt, switch the heater off and on again.