Kärcher HDS 7/12 M Service Manual page 47

1 Rubber collar
2 Lock
3 Air door, air volume adjustment
4 Stop screw
5 Burner blower
1 Solenoid valve
2 Coupling unit
3 Connection pressure line
4 Setting fuel pressure
5 Fuel pump
6 Fastening screw
Uninstall fuel pump
Detach pressure line.
–
Unscrew locking screws.
–
Remove the fuel pump.
–
Fuel pump
The fuel pump is connected directly to the motor shaft via
the coupling piece and the blower wheel. It also feeds fuel
from the tank and back via the return during cold water op-
eration. This lubricates the toothed wheel pump.
During warm water operation, the installed solenoid valve
and part of the fuel reaches the burner through the fuel
nozzle and is ignited there.
The fuel pressure is adjusted via the central setting screw.
During dry runs, the fuel pump will block.
The coupling piece serves as a nominal breaking point.
1 Fastening screws blower cover
2 Fastening screw blower wheel
3 Coupling unit
4 Blower wheel
5 Fuel pump
Burner blower
The blower supplies the burner with combustion air.
The air flap is used to adjust the air value to optimised
combustion values.
The blower wheel is mounted to the motor shaft by means
of 2 feather keys.
English 5.906-432.0 Rev. 00 (06/15)
47