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Siemens Building Technologies
Basic Documentation QAA73.110 Room unit
CE1P2284en
HVAC Products
Handling
10.07.2002
2.10 Operational faults
No display on the room unit:
•
Is the heating plant's main switch turned on?
•
Are the fuses in order?
•
Check the wiring
Room unit displays a wrong time of day or a wrong date:
•
Set the right time of day, the right date and the year on the room unit if the
QAA73.110 is the clock master
•
Set the correct time of day and the date on the clock master (if present)
Boiler control does not switch on
•
Does boiler control really have to operate?
•
Press boiler control’s lock-out reset button
•
Check the control thermostat (TR) and the manual reset safety limit thermostat
(STB)
•
Check wiring and fuse of boiler control
•
Check the communication link to boiler control
The room temperature does not agree with the required temperature level:
•
Does the room temperature setpoint agree with the required temperature level?
•
Is the required operating mode indicated?
•
Are weekday, time of day and the displayed heating program correct?
(Info displays)
•
Has the heating curve slope been correctly set?
•
Check wiring of outside sensor
•
Has the ”Nominal room temperature setpoint” with the ”Parallel displacement of the
heating curve” been calibrated based on the effective room temperature?
•
Check boiler control
D.h.w. is not being heated:
•
Has the button for d.h.w. heating been pressed?
•
Check setpoint of the d.h.w. temperature
•
Check d.h.w. function of boiler control
Room unit
Boiler controller
Room temperature
D.h.w.