Vaillant ecoTEC VU 466/4, Installation And Maintenance Instructions Manual

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Installation and maintenance instructions ecoTEC 0020029172_03
Code Meaning Cause
F. 0 Break Flow NTC NTC plug not plugged in or has come loose, multiple plug on the
PCB not plugged in correctly, interruption in cable harness, NTC
defective
F. 1 Break Return NTC NTC plug not plugged in or has come loose, multiple plug on the
PCB not plugged in correctly, interruption in cable harness, NTC
defective
F.10 Short circuit Flow NTC Short to ground/short circuit in cable harness, NTC defective
F.11 Short circuit Return NTC Short to ground/short circuit in cable harness, NTC defective
F.13 Short circuit Cylinder sensor Short to ground/short circuit in cable harness, moisture in plug,
NTC defective
F.20 Safety shutdown Temperature limiter Incorrect earth connection between cable harness and boiler, flow
or return NTC defective (loose connection), black discharge via
ignition cable, ignition plug or ignition electrode
F.22 Safety shutdown Water lack/dry combustion No or insufficient water in the boiler, cable for pump, water
pressure sensor or flow rate sensor loose/not plugged in/defective,
pump blocked or defective, pump output too low, non-return valves
blocked/incorrectly installed, minimum quantity of circulation
water not reached
F.23 Safety shutdown Over temperature-spread NTC Pump blocked, insufficient pump output, air in boiler, system
pressure too low, flow and return NTC interchanged
F.24 Safety shutdown Temperature rises too quickly Pump blocked, insufficient pump output, air in boiler, system
pressure too low, non-return valves blocked/incorrectly installed,
flow and return NTC interchanged
F.25 Safety shutdown Excessive flue temperature Break in plug connection for optional flue gas safety thermostat,
break in cable harness
F.27 Safety shutdow Flame simulation Moisture on the PCB, PCB (flame monitor) defective, gas solenoid
valve leaking
F.28 Failure during start-up: Ignition failed Gas meter defective, gas pressure monitor has been triggered, air
in gas, gas inlet working pressure too low,
Thermal isolator device (TAE) has been triggered, condensate duct
blocked, failure at gas valve, multiple plug on PCB incorrectly
plugged in, break in cable harness, ignition system (ignition
transformer, ignition cable, ignition plug, ignition electrode)
defective, ionisation current interrupted (cable, electrode),
incorrect earthing of boiler, PCB defective
F.29 Failure during operation: Re-ignition failed Gas feed interrupted from time to time, flue gas recirculation,
condensate duct blocked, faulty earthing of boiler
F.32 Failure Fan Plug at fan not correctly plugged in, multiple plug on PCB not
correctly plugged in, break in cable harness, fan blocked, Hall
sensor defective, PCB defective
F.49 Failure eBUS Short-circuit on eBUS, eBUS overload or two power supplies with
different polarities on the eBUS
F.61 Failure Activation fuel valve short circuit/short to ground in cable harness for gas valve, gas
valve defective (coils shorted to ground), PCB defective
F.62 Failure Off delay fuel valve delayed shutdown of gas valve, delayed extinguishing of flame
signal, gas valve leaking, PCB defective
F.63 Failure EEPROM PCB defective
F.64 Failure Electronics/sensor Flow or return NTC short circuited, PCB defective, recirculation
F.65 Failure Electronics temperature PCB too hot due to external effect, PCB defective
F.67 Failure Electronics/flame Implausible flame signal, PCB defective
F.70 Invalid application ID Spare part case: Display and PCB changed at the same time and
boiler variant not re-set
F.71 Failure Flow NTC Flow sensor signalling constant value -> flow sensor defective
F.72 Failure Flow/return NTC Temperature spread between flow sensor and return sensor too
large -> flow and/or return sensor defective
F.73 Failure Water pressure sensor Interruption/short-circuit of water pressure sensor, interruption/
short-circuit to GND in supply line to water pressure sensor
Table 9.4 Fault messages (continued on next page)
Troubleshooting 9