Technical data

9 Repair Thermo 230 / 231 / 300 / 301 / 350
908
9.2.5 Control Unit, Replacement
NOTE
For replacement of the control unit the burner head
may be left installed and must only be swung open for
disconnection of electrical connector (8, Fig. 903).
In removed condition ensure that igniter electrodes are
not bent and nozzle is not damaged.
If a control unit 1572 is substituted with a control unit
1572D, perform procedure according to 9.1.2.1.
9.2.5.1 Removal
1. Disconnect all electrical connections from control unit
(23, Fig. 903).
2. Swing burner head open (refer to 8.5.1) and
disconnect electrical connector (8).
3. Remove flame sensor (refer to 9.2.8.1).
4. Remove combustion air fan (refer to 9.2.4.1).
5. Carefully withdraw control unit (23) in axial direction
from burner head (17) and remove.
6. Perform procedures on components after
disassembly (refer to 9.1.1).
9.2.5.2 Installation
1. Carefully push control unit (23, Fig. 903) in axial
direction against stop into burner head (17).
2. Install combustion air fan (refer to 9.2.4.2).
3. Make all electrical connections on control unit (23).
4. Install flame sensor (refer to 9.2.8.2).
5. Connect electrical connector (8).
9.2.6 Fuel Pump, Replacement
9.2.6.1 Removal
1. Remove burner (refer to 9.2.3.1).
2. Using screwdriver lever off igniter electrodes
(3, Fig. 903) from igniter box (1) and remove.
3. Remove disk (6, Fig. 903) with heating cartridge
(if installed).
4. Disconnect electrical connector (8).
NOTE
During the following step ensure that escaping fuel is
immediately neutralized and properly disposed of.
5. Remove screws (9) with lock washers.
6. Withdraw fuel pump (10) together with solenoid valve
(7) and remove.
7. Remove and discard O-rings (12) and filter screen
(11).
8. Remove solenoid valve (7) from fuel pump (10) as
required.
9. Perform procedures on components after
disassembly (refer to 9.1.1).
9.2.6.2 Installation
1. Install solenoid valve (7, Fig. 903) on fuel pump (10)
if required.
2. Fit new O-ring (12) and filter screen (11) on fuel pump
(10).
3. Position fuel pump (10) for installation and secure
with screws (9) and lock washers.
4. Tighten screws with 5 Nm + 1 Nm.
5. Connect electrical connector (8).
6. Plug on disk (6) and mount heating cartridge.
7. Plug on igniter electrodes (3, Fig. 904).
8. Install burner (refer to 9.2.3.2).
9.2.7 High Pressure Nozzle, Replacement
9.2.7.1 Removal
1. Remove burner (refer to 9.2.3.1).
2. Using screwdriver lever off igniter electrodes
(3, Fig. 903) from igniter box (1) and remove.
3. Remove disk (6, Fig. 903) with heating cartridge
(if installed).
4. Disconnect electrical connector (8) of the heating
cartridge.
5. Unscrew high pressure nozzle (4).
NOTE
Ensure cleanliness is maintained when installing the
nozzle. Only touch the nozzle at its hexagon surface.
9.2.7.2 Installation
1. Screw in high pressure nozzle (4, Fig. 903) and
tighten with 20 Nm.
2. Connect electrical connector (8) of the heating
cartridge.
3. Plug on disk (6) and mount heating cartridge.
4. Plug on igniter electrodes (3, Fig. 903).
5. Install burner (refer to 9.2.3.2).