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Room unit
Boiler controller
Room temperature
D.h.w.
Siemens Building Technologies
HVAC Products
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
Basic Documentation QAA73.110 Room unit
Error! Style not defined.
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CE1P2284en
19.06.2002
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