Appendix
52
Installation and maintenance instructions Energy
7
0020300875_01
Fault code
Meaning
Possible cause
F.12
and
F.91
Short circuit: Cylinder temperature
sensor
NTC sensor defective, short circuit in the cable harness, cable/housing
F.13
Short circuit: Temperature sensor for the
domestic hot water cylinder
NTC sensor defective, short circuit in the cable harness, cable/housing
F.20
Safety shutdown: Overheating temperat-
ure reached
Incorrect earth connection between cable harness and product, flow or return
NTC defective (loose connection), stray spark via ignition cable, ignition plug
or ignition electrode
F.22
Safety shutdown: Water deficiency in the
boiler
No or insufficient water in the product, water pressure sensor de-
fective, cable to the pump or to the water pressure sensor loose/not
connected/defective
F.23
Safety shutdown: Temperature spread
too great (NTC1/NTC2)
Pump blocked, insufficient pump output, air in product, flow and return NTC
sensors connected the wrong way round
F.24
Safety shutdown: Temperature rise too
fast
Pump blocked, insufficient pump output, air in product, system pressure too
low, non-return valve blocked/incorrectly installed
F.25
Safety shutdown: Flue gas temperature
too high
Break in plug connection for optional flue gas safety cut-out (SCO), break in
cable harness
F.27
Safety shutdown: Fault in flame detec-
tion
Moisture on the electronics, electronics (flame monitor) defective, gas solen-
oid valve leaking
F.28
Fault: Ignition unsuccessful when starting
up
Gas meter defective or gas pressure switch has triggered, air in gas, gas
flow pressure too low, thermal cut-out has triggered, incorrect gas injector,
incorrect spare gas valve assembly, fault on the gas valve assembly, mul-
tiple plug on PCB incorrectly plugged in, break in cable harness, ignition sys-
tem (ignition transformer, ignition cable, ignition plug, ignition electrode) de-
fective, ionisation flow interrupted (cable, electrode), incorrect earthing of
product, electronics defective
Condensate siphon blocked
F.29
Fault: Flame loss
Gas supply temporarily stopped, flue gas recirculation, incorrect earthing of
product, ignition transformer has spark failure
Condensate siphon blocked
F.32
Fan frost protection function active: Fan
speed outside the tolerance values
Plug on fan not correctly plugged in, multiple plug on PCB not correctly
plugged in, break in cable harness, fan blocked, Hall sensor defective, elec-
tronics defective
F.49
eBUS fault: Voltage too low
Short circuit on eBUS, eBUS overload or two power supplies with different
polarities on the eBUS
F.61
Fault: Gas valve assembly control
Short circuit/short-to-ground in cable harness to gas valve assembly, gas
valve assembly defective (coils shorted to earth), electronics defective
F.62
Fault: Gas valve switch-off control
Delayed switch-off 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 / sensor / analogue-to-
digital converter
Flow or return NTC short circuited, electronics defective
F.65
Fault: Electronics temperature too high
Electronics overheating due to external influences, electronics defective
F.67
Value sent back by ASIC is incorrect
(flame signal)
Implausible flame signal, electronics defective
F.68
Fault: Unstable flame (analogue input)
Air in gas, gas flow pressure too low, incorrect air ratio, incorrect gas in-
jector, ionisation flow interruption (cable, electrode)
F.70
Invalid product code (DSN)
Display and PCB replaced at same time and Device Specific Number not
reset, wrong or missing output coding resistor
F.71
Fault: Flow/return temperature sensor
Flow temperature sensor signalling constant value: Flow temperature sensor
incorrectly positioned on flow pipe, flow temperature sensor defective
F.72
Fault: Deviation in the water pressure
sensor/return temperature sensor
Flow/return NTC temperature difference too great
→
flow and/or return tem-
perature sensor defective
F.73
Fault: Water pressure sensor not con-
nected or has short-circuited
Interruption/short circuit of water pressure sensor, interruption/short circuit
to GND in supply pipe to water pressure sensor or water pressure sensor
defective
F.74
Fault: Electrical problem in the water
pressure sensor
Line to water pressure sensor has a short circuit to 5 V/24 V or internal fault
in the water pressure sensor
F.75
Fault: Pressure sensor
Pressure switch defective
F.76
The safety cut-out in the primary heat
exchanger is defective
Safety cut-out feedback does not match the gas valve assembly feedback
F.77
Fault: Condensate or smoke
No response, flue non-return flap defective