Vaillant ecotec plus Installation And Maintenance Instructions Manual page 48

9 Troubleshooting
Code Meaning
F. 0 Break Flow NTC
F. 1 Break Return NTC
F.10 Short circuit Flow NTC
F.11 Short circuit Return NTC
F.13 Short circuit Cylinder sensor
F.20 Safety shutdown Temperature limiter
F.22 Safety shutdown Water lack/dry combustion
F.23 Safety shutdown Over temperature-spread NTC
F.24 Safety shutdown Temperature rises too quickly
F.25 Safety shutdown Excessive flue temperature
F.27 Safety shutdow Flame simulation
F.28 Failure during start-up: Ignition failed
F.29 Failure during operation: Re-ignition failed
F.32 Failure Fan
F.49 Failure eBUS
F.61 Failure Activation fuel valve
F.62 Failure Off delay fuel valve
F.63 Failure EEPROM
F.64 Failure Electronics/sensor
F.65 Failure Electronics temperature
F.67 Failure Electronics/flame
F.70 Invalid application ID
F.71 Failure Flow NTC
F.72 Failure Flow/return NTC
F.73 Failure Water pressure sensor
Table 9.4 Fault messages (continued on next page)
48
Cause
NTC plug not plugged in or has come loose, multiple plug on the
PCB not plugged in correctly, interruption in cable harness, NTC de-
fective
NTC plug not plugged in or has come loose, multiple plug on the
PCB not plugged in correctly, interruption in cable harness, NTC de-
fective
Short to ground/short circuit in cable harness, NTC defective
Short to ground/short circuit in cable harness, NTC defective
Short to ground/short circuit in cable harness, moisture in plug,
NTC defective
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
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
Pump blocked, insufficient pump output, air in boiler, system
pressure too low, flow and return NTC interchanged
Pump blocked, insufficient pump output, air in boiler, system
pressure too low, non-return valves blocked/incorrectly installed,
flow and return NTC interchanged
Break in plug connection for optional flue gas safety thermostat,
break in cable harness
Moisture on the PCB, PCB (flame monitor) defective, gas solenoid
valve leaking
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
Gas feed interrupted from time to time, flue gas recirculation,
condensate duct blocked, faulty earthing of boiler
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
Short-circuit on eBUS, eBUS overload or two power supplies with
different polarities on the eBUS
short circuit/short to ground in cable harness for gas valve, gas
valve defective (coils shorted to ground), PCB defective
delayed shutdown of gas valve, delayed extinguishing of flame
signal, gas valve leaking, PCB defective
PCB defective
Flow or return NTC short circuited, PCB defective, recirculation
PCB too hot due to external effect, PCB defective
Implausible flame signal, PCB defective
Spare part case: Display and PCB changed at the same time and
boiler variant not re-set
Flow sensor signalling constant value -> flow sensor defective
Temperature spread between flow sensor and return sensor too
large -> flow and/or return sensor defective
Interruption/short-circuit of water pressure sensor, interruption/
short-circuit to GND in supply line to water pressure sensor
Installation and maintenance instructions ecoTEC plus 0020214490_00