Appendix
0020233500_01 auroCOMPACT Installation and maintenance instructions
51
Code
Meaning
Cause
F.28
Failure during start-up: Ignition unsuccessful
Gas meter defective or gas pressure monitor has triggered, air in gas,
gas flow pressure too low, thermal isolator device (TAE) has triggered,
condensate route blocked, incorrect gas injector, incorrect spare part
gas valve assembly, fault on the gas valve assembly, multiple plug on
PCB incorrectly plugged in, break in cable harness, ignition system
(ignition transformer, ignition cable, ignition plug, ignition electrode)
defective, ionisation flow interrupted (cable, electrode), incorrect earthing
of product, electronics defective
F.29
Failure during operation: Re-ignition unsuccess-
ful
Gas supply temporarily stopped, flue gas recirculation, condensate route
blocked, defective earthing of product, ignition transformer has spark
failure
F.32
Fan fault
Plug on fan not correctly plugged in, multiple plug on PCB not correctly
plugged in, break in cable harness, fan blocked, Hall sensor defective,
electronics defective
F.35
Lack of air in combustion unit
Fan speed not correct, air supply or smoke outlet blocked, plug not
correctly connected to fan, multiple plug on PCB not correctly connected,
break in cable harness, fan blocked, Hall sensor defective, electronics
defective
F.42
Coding resistor fault (possible in combination
with F.70)
Short circuit/interruption in output range coding resistor (in cable harness
at heat exchanger) or gas group resistor (on PCB)
F.47
Detachment of domestic hot water sensor in
cylinder outlet (flow rate detection)
NTC defective, NTC cable defective, defective plug connection on NTC
F.48
Domestic hot water sensor short circuit at cylin-
der outlet (flow rate detection)
NTC defective, short circuit in cable harness, cable/housing
F.49
Fault: eBUS
Short circuit on eBUS, eBUS overload or two power supplies with differ-
ent polarities on the eBUS
F.52
Mass flow sensor connection fault
Mass flow sensor not connected/disconnected, plug not connected or
incorrectly connected
F.53
Mass flow sensor fault
Gas flow pressure too low, filter under Venturi filter cap wet or blocked,
mass flow sensor defective, internal pressure measuring point in Venturi
blocked (do not use lubricant on Venturi O-ring.)
F.54
Gas pressure fault (in combination with
F.28/F.29)
No or insufficient gas inlet pressure, gas stopcock closed
F.56
Fault: Mass flow sensor control
Gas valve assembly defective, cable harness to gas valve assembly
defective
F.57
Fault during comfort protection mode
Ignition electrode highly corroded
F.61
Gas valve assembly control system fault
–
Short circuit/short to earth in cable harness for the gas valve as-
sembly
–
Gas valve assembly defective (coils shorted to earth)
–
Electronics defective
F.62
Gas valve assembly fault, switch-off delay
–
Delayed shutdown of gas valve assembly
–
Delayed extinguishing of flame signal
–
Gas valve assembly leaking
–
Electronics defective
F.63
Fault: EEPROM
Electronics defective
F.64
Fault: Electronics/NTC
Flow or return NTC short circuited, electronics defective
F.65
Fault: Electronics temp.
Electronics overheating due to external influences, electronics defective
F.67
Fault: Electronics/flame
Implausible flame signal, electronics defective
F.68
Fault: Unstable flame signal
Air in gas, gas flow pressure too low, incorrect air ratio, condensate
route blocked, incorrect burner jet, ionisation flow interruption (cable,
electrode), flue gas recirculation, condensate route, electronics defective
F.70
Invalid device specific number (DSN)
If spare parts fitted: Display and PCB replaced at same time and DSN
not reset, incorrect or missing output range coding resistor
F.71
Flow temperature sensor fault
Flow temperature sensor signalling constant value:
–
Flow temperature sensor incorrectly positioned on the flow pipe
–
Flow temperature sensor defective
F.72
Flow and/or return temperature sensor fault
Flow/return NTC temperature difference too great
→
flow and/or return
temperature sensor defective
F.73
Water pressure sensor signal in the wrong range
(too low)
Interruption/short circuit of water pressure sensor, interruption/short
circuit to GND in supply line to water pressure sensor or water pressure
sensor defective
