Technical data

Thermo 230 / 231 / 300 / 301 / 350 8 Servicing
807
Rigid pipes made of unalloyed or alloyed steel with a
minimum wall thickness of 1.0 mm have to be used as
exhaust line or flexible pipes made of alloyed steel only.
The exhaust pipe is secured to the air heater e.g. with a
clamp.
Permissible exhaust line dimensions:
– inner diameter: 70 mm
– max. length: 5 m without the exhaust extension
– max. bend: 270°
As an alternative an exhaust deflector must be installed
cleared by Spheros.
8.7 Removal and Installation
CAUTION
In installed condition only the following disassembly or
removal procedures are permitted should enough space
for removal allow such action:
– replacement of temperature limiter
– replacement of temperature sensor
– replacement of combustion air fan
– replacement of burner
– replacement of igniter box
– replacement of flame sensor
– replacement of combustion chamber
8.7.1 Heater, Removal and Installation
8.7.1.1 Removal
1. Disconnect connectors of cable harness in vehicle
and of circulation pump.
2. Disconnect combustion air intake on heater if
required.
3. Loosen clamp on exhaust outlet.
4. Loosen fuel supply and return line connections and fit
dummy plugs.
Close water cocks as applicable.
5. Loosen hose clamps on coolant hoses, disconnect
hoses and fit dummy plugs.
6. Remove 3 screws and washers or 4 screws and
washers.
7. Remove heater.
8.7.1.2 Installation
1. Locate heater for installation and secure with 3 screws
and washers or 4 screws and washers.
2. Secure line on exhaust outlet using clamp.
3. Slide on coolant hoses and fasten with hose clamps.
Torque clamps with 1.5 Nm. Open water cocks.
4. Connect fuel supply and return lines and tighten
connections or screw tight with banjo bolt and new
gaskets.
5. Secure combustion air inlet line on heater as
applicable.
6. Connect electrical connectors of cable harness in
vehicle and to circulation pump.
7. Bleed fuel supply system.
8. Bleed coolant circuit.
8.7.2 Temperature Limiter, Replacement
NOTE
The replacement procedure for the temperature limiter is
identical with the heater installed or removed.
Perform replacement in accordance with 9.2.1.
8.7.3 Temperature Sensor, Replacement
NOTE
The replacement procedure for the temperature sensor is
identical with the heater installed or removed.
Perform replacement in accordance with 9.2.2.
WARNING
Prior to replacement of temperature sensor in installed
condition relief overpressure in cooling system by opening
the cooling circuit sealing element.
If required also allow heater to cool down and have
collector vessel ready to collect escaping coolant.
8.7.4 Burner, Replacement
NOTE
The replacement procedure for the burner is identical with
the heater installed or removed.
Perform replacement in accordance with 9.2.3.
WARNING
The igniter box operates on high voltage. Prior to replace-
ment of burner disconnect electrical connectors of cable
harness in vehicle to avoid lethal accidents.
8 7.5 Igniter Box, Replacement
NOTE
The replacement procedure for the igniter box is identical
with the heater installed or removed.
Perform replacement in accordance with 9.2.7.
WARNING
The igniter box operates on high voltage. Prior to replace-
ment of igniter box disconnect electrical connectors of
cable harness in vehicle to avoid lethal accidents.