Daikin GCU compact Series Installation And Operating Instructions Manual page 60

10 Errors and faults
Fault
Burner fan not running No mains voltage on burner
despite burner demand
Plug connections on PCB control panel or combus-
tion control are loose
Burner blower defective (bearing has seized)
No gas pressure
Air in the gas line
Gas control block does not open
No ignition
Burner starting is hard Start delay due to bad ignition
No ignition Ignition electrodes short circuited
Distance of ignition electrodes too large
Ignition electrodes contaminated or humid
Ignition electrodes burnt out
Insulating body cracked
Ignition transformer defective
Ignition cable defective, sparking
Automatic combustion control faulty
Loud operating noises Wrong burner setting
Bearing damage on burner fan
Thermo-acoustics
Loudly whistling mech- Burner blower bearing defective
anical noise
STB switch off Water throughput too low due to air inclusion
Water flow too low due to valves closing too quickly
in the entire heating network
Pump down
Disturbing circulation Pump pressure too high
noises
Badly balanced heat distribution system
Tab. 10-1 Possible faults on the GCU compact
(21)
see "RoCon BF controller" documentation
Installation and operating instructions
60
Possible cause Possible solution
▪ Insert X1 connector on combustion control until it clicks in
place.
▪ Check voltage at the terminals L-N of the X1 connector.
▪ Check/ renew fuse.
▪ Check/ connect the plug connections.
▪ Replace the burner blower.
▪ Inspect the gas connections.
▪ Vent the gas line.
▪ Check the plug connections between the safety gas control
block and combustion control and connect correctly.
▪ Check the safety gas control block (zero pressure during igni-
tion).
▪ Replace the safety gas control block.
▪ Replace the combustion control.
▪ See "No ignition" fault.
▪ Adjust the ignition electrodes.
▪ Check the starting output and adjust as required.
▪ Check the ignition electrodes, adjust or replace as required.
▪ Check the ignition electrodes and adjust as required.
▪ Clean the ignition electrodes and check the burner settings.
▪ Replace the ignition electrodes.
▪ Replace the ignition electrodes.
▪ Replace the ignition transformer.
▪ Replace the ignition cable and determine cause.
▪ Replace the combustion control.
▪ Re-adjust the burner setting.
▪ See "Loudly whistling mechanical noise" fault.
▪ Insert the supply air manifold (see
Venturi nozzle.
▪ Re-adjust the burner setting.
▪ Replace the burner blower.
▪ Vent the system.
▪ Use slow closing or timed valves, install overflow valve if re-
quired.
▪ Check the mains and PWM control signal connection, replace
the pump if required.
▪ Throttle maximum pump output (reduce the setting of the
[Max Perform Pump] parameter gradually – not below 65 %).
(21)
▪ Carry out hydraulic balancing.
Floor-standing gas condensing boiler with integrated heat storage
Fig. 7-3, item 13) on the
Gas Combi Unit
008.1543899_02 – 04/2019 – EN