Rotex GCU compact - Page 50

50
ROTEX GCU compact - 
10 x Faults and malfunctions
1) See documentation "ROTEX RoCon BF Controller"
Tab. 10-1 Possible faults on the GCU compact
Burner fan not run-
ning despite burner
demand
No mains voltage on burner
Ɣ Insert X1 plug on automatic firing until it clicks in place.
Ɣ Check voltage at the terminals L-N of the X1 plug
Ɣ Check/ renew fuse.
Plug conne
ctions switching panel PCB or auto-
matic firing are loose
Ɣ Check/ insert plug connections
Burner blower defective (bearing has seized)
Ɣ Replace the burner blower.
No gas pressure
Ɣ Inspect the gas conn
ections.
Air in the gas line
Ɣ Vent the gas line.
Gas control block does not open
Ɣ Check the plug connections between the safety gas
control block and firing unit and insert correctly.
Ɣ Check the safety gas control block (zero pressure
during the
ignition).
Ɣ Replace the safety gas control block.
Ɣ Replace the combustion controller.
No ignition
Ɣ See fault "No i
gnition".
Burner starting is hard Start delay due to bad ignition
Ɣ Adjust ignition electrodes
Ɣ Check the starting output and adjust as necessary.
No ignition Ignition electrodes short circuited
Ɣ Check the ignition electrodes, adjust or replace as
necessary.
Distance of ignition electrodes too large
Ɣ Check the ignition electrodes and adjust where
necessary.
ignition e
lectrodes contaminated or humid
Ɣ Clean the ignition electrodes and check the burner
settings.
Ignition electrodes burnt out
Ɣ Change ignition electrodes
Insulating body cracked
Ɣ Change ignition electrodes
Ignition transformer defective
Ɣ Replace ignition transformer
Ignition cable defective, arking
Ɣ Change ignition cable and determine the cause
Firing unit faulty
Ɣ Replace the combustion controller.
Loud operating noises Wrong burner setting
Ɣ Re-adjust the burner setting.
Bearing damage on burner fan
Ɣ See fault "Loud, whistling mechanical noise".
Loud, whistling
mechanical noise
Burner blower bearing defective
Ɣ Replace the burner blower.
STL switch off Water throughput too low due to air inclusion
Ɣ Vent system
Water flow too low due to valves closing too
quickly along the entire heating network
Ɣ Use slow closing or timed valves, if needed, install
overflow valve
Pump standstill
Ɣ Check mains and PWM control signal connection,
replace pump if necessary.
Malfunction Possible cause Possible solution