H3-72-01
51
For internal use only
7.5.10 Boiler and water level pin scaled
Fault mechanism
Scaling of the boiler is detected during the process of altitude adjustment. If the difference between the
temperatures of the heating spiral and the water, taken with several measurements, is too great, or if the
water level pin has been recognized as being scaled several times, an alarm message will be indicated.
If the temperature no longer rises on altitude adjustment, the maximum recorded heater spiral
temperature and water temperature are compared. Should the heater spiral temperature be higher by a
certain level (EEPROM parameter), the boiler will be recognised as being scaled. The boiler is also
considered to be scaled if, subsequent to initial filling of the boiler, the conductance of the water shortly
before altitude adjustment is above a certain level (water level pin scaled, EEPROM value). If the boiler
has been recognized as being scaled several times (EEPROM parameter), an
alarm message “A10”
will be indicated at the end of the current program.
Possible causes of faults
•
Boiler and water level pin scaled
•
Boiler scaled
•
Water level pin scaled
•
The appliance is located at an altitude of more than 3,500 m above sea level
8.
Circuit diagrams
See next pages.