Rotex A1 BO 15bio - Rectifying STL Fault

6 x Faults and malfunctions
34
BA ROTEX A1 BO - 10/2007
Tab. 6-3 Possible malfunctions on the A1 BO (Part 2)
6.4 Rectifying STL fault
When the STL indicator (fig. 4-1, pos. 3 and fig. 4-3, pos. 3) lights up, it indicates the boiler overheating. The safety temperature
limiter (STL) shuts off the system and locks it.
• Before unlocking the STL, determine the cause for the boiler overheating and rectify it (see tab. 6-3).
Unlocking the STL
• Remove the sound insulation hood (see fig. 5-1).
• Unscrew the cover on the STL.
• Unlock STL switch with pointed object.
• Screw on STL switch.
• Install sound insulation hood.
Malfunction Possible cause Possible solution
Oil pump does not pump
any oil
Stop valve at oil filter or in suction line closed
• Open stop valve
Oil pump or coupling faulty
• Rectification by the heating expert
Oil line has leakage (pump suctions air)
Filter blocked or leaking
Solenoid valve not opening
Oil atomisation not
uniform – heavy soot
deposit in flame tube
Oil nozzle loose, clogged or worn out
• Rectification by the heating expert
Oil nozzle spraying angle is wrong
No oil flow Oil nozzle or LE diaphragm valve blocked
• Rectification by the heating expert
Mixer device has thick
layer of oil or heavy
carbon deposits
Air supply insufficient
• Check air supply line for clogging
• Ambient air dependent operation: Check air supply opening
(min. 150 cm
2
unlockable air supply opening)
Flue gas pipe of the LAS is leaking
• Rectification by the heating expert
Burner setting wrong
Oil nozzle is wrong size
Combustion air quantity wrong
Suction line draws air (leakage)
Automatic flame guard
does not actuate
Flame guard contaminated or defective
• Rectification by the heating expert
Glass on light tube dirty
Flue gas temperature
sensor switch off
Flue gas temperature too high
• Clean the boiler
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 or time-offset closing valves, if necessary have
overflow valve fitted
Pump standstill
• Check mains connection and, if necessary, replace the pump
Storage tank switched off in operation without hot water
storage tank
• Have the storage tank temperature sensor disconnected
• Switch off storage tank charging circuit
WARNING!
Risk of burns due to hot boiler body.
• Do not touch any metallic parts on the boiler.
• Let the boiler cool down.
• Wear protective gloves.