Rotex A1 BO, Installation And Maintenance Instructions Manual

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9 x Faults and malfunctions
62 FA ROTEX A1 BO - 10/2007
Tab. 9-3 Possible malfunctions on the A1 BO (Part 3)
9.3 Control unit fault signals
The control unit detects malfunctions, e.g. sensor disruptions or short-circuits. The type of malfunction is displayed via a fault
code. The fault codes are explained in the documentation of the relevant ROTEX control.
9.4 Burner malfunctions
The LED in the reset button of the automatic firing units (fig 6-1, pos. 9) indicates the processes of the burner control. In the
normal mode , the LED transmits a brief flashing signal, followed by a long pause.
LED display in the event of a malfunction :
– LED burns steadily, the burner is shut off and locked.
– The continuous lighting is interrupted every 10 seconds and a flash code is broadcast which gives information about the
cause of the last fault.
Fig. 9-1 Fault codes of the automatic firing units
I short signal
l long signal
— Pause
Malfunction Possible cause Possible solution
Mixer device has thick
layer of oil or heavy
carbon deposits Air supply line contaminated/clogged
• Clean air supply line
Flue gas pipe of the LAS is leaking
• Seal the flue gas pipe, change seal
Burner setting wrong
• Check/correct burner setting
Oil nozzle is wrong size
• Check/change nozzle type
Combustion air quantity wrong
• Measure fan pressure, correct burner setting
Suction line draws air (leakage)
• Seal suction line
Soot formation on the
air nozzle Recirculation too low
• Open recirculation slightly
Solenoid valve at oil
pump does not open Coil defective
• Change coil
Automatic firing unit faulty
• Change automatic firing unit
Automatic flame guard
does not actuate Flame guard contaminated or defective
• Clean or change flame guard
Glass on light tube dirty
• Clean or change glass or light tube
STL switch off Water throughput too low due to air inclusion
• Vent system
Water flow too low due to valves closing too quickly
along the entire heating network
• Use slow closing or timed valves, if needed, install overflow valve
Pump standstill
• Check network connection, change pump if necessary
Storage tank switched off in operation without
hot water storage tank
• Disconnect storage temperature sensor
• Switch off storage tank charging circuit
Flue gas temperature
sensor switch off Flue gas temperature too high
• Clean the boiler
Flash Code Cause of the fault
l l l l l No flame signal within safety period
l l l l l External light during pre-ventilation time/ pre-ignition time
l l l l l Contact release thermostat does not close within 400 s
l l l l l — l l l l l Manual fault shutdown