Unit Function
HDS Middle Range / HDS Premium Range
Page 20 / 127
Service Manual 04.2008
2.2.4 Error messages with service requirement
Display
Note
Explanation
Low-water protection sticks
10 short start-ups/leakage
Contactor does not switch
Temperature sensor (NTC) is defective
Flame sensor detects impermissible state
Check low-water protection.
Remove leaks in the high-
pressure system.
Check contactor.
Check current transformer
installation.
This fault is not saved.
Check NTC
NTC cable chafed bare
Possible causes:
- Fuel solenoid valve
- Fuel line/filter
- External light
- Inspection glass is sooty
- Scale in combustion chamber
- Fuel empty and
fuel empty signal is defective
RFID read-write electronics are defective
Check connection with RFID
read-write electronics.
Note
One display is used here for several faults. It may be possible to localise the fault by reading
out the fault memory.