Appendix
0020283671_03
Energy
2
Installation
and
maintenance
instructions
35
Fault code
Meaning
Possible cause
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
system (ignition transformer, ignition cable, ignition plug, ignition electrode)
defective, 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
F.78
Interruption to DHW outlet sensor at
external control
UK link box is connected, but domestic hot water NTC not bridged
F.83
Fault: Dry fire
When the burner starts, the temperature change registered at the flow or
return temperature sensor is non-existent or too small: Insufficient water
in the product, the flow or return temperature sensor is not in the correct
position on the pipe
F.84
Fault: Flow/return temperature sensor
Values not consistent, difference < -6 K
Flow and return temperature sensors signalling implausible values: Flow and
return temperature sensors have been inverted, flow and return temperature
sensors have not been correctly installed
F.85
Fault: Temperature sensor
The flow and/or return temperature sensors have been installed on the same
pipe/incorrect pipe
Temperature sensor not connected or is connected incorrectly
F.86
Fault: Underfloor heating contact
Underfloor heating contact open, sensor disconnected or defective
F.87
Fault: Electrodes
Electrodes not connected or they are connected incorrectly, short circuit in
the cable harness
F.88
Fault: Gas valve assembly
Gas valve assembly not connected or it is connected incorrectly, short circuit
in the cable harness