Vaillant ecoFitpure 615 Boiler Fault Codes

Vaillant Boilers
 Code Meaning Possible Cause
F00 Fault: Flow temperature sensor NTC plug not plugged in or has come loose, multiple plug on the PCB not plugged in correctly, interruption in cable harness, NTC sensor defective
F01 Fault: Return temperature sensor NTC plug not plugged in or has come loose, multiple plug on the PCB not plugged in correctly, interruption in cable harness, NTC sensor defective
F10 Short circuit: Flow temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing
F11 Short circuit: Return temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing
F12 & F91 Short circuit: Cylinder temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing
F13 Short circuit: Domestic hot water cylinder temperature sensor NTC sensor defective, short circuit in the cable harness, cable/casing
F20 Safety switch-off: Overheating temperature reached Incorrect earth connection between cable harness and product, flow or return NTC defective (loose connection), black discharge via ignition cable, ignition plug or ignition electrode
F22 Safety switch-off: Low water pressure in the boiler No or insufficient water in the product, water pressure sensor defective, cable to the pump or to the water pressure sensor loose/not connected/defective
F23 Safety switch-off: Temperature difference too great (NTC1/NTC2) Pump blocked, insufficient pump output, air in product, flow and return NTC sensors connected the wrong way round
F24 Safety switch-off: Temperature rise too fast Pump blocked, insufficient pump output, air in product, system pressure too low, non-return valve blocked/incorrectly installed
F25 Safety switch-off: Flue gas temperature too high Break in plug connection for optional flue gas safety cut-out (STB), break in cable harness
F27 Safety switch-off: Fault in flame detection Moisture on the electronics, electronics (flame monitor) defective, gas solenoid valve leaking
F28 Fault: Ignition unsuccessful when starting up Gas meter defective or gas pressure monitor has triggered, air in gas, gas flow pressure too low, thermal isolator device (TAE) has triggered, incorrect gas restrictor, incorrect spare gas valve, fault on the 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 product, electronics defective
F29 Fault: Flame loss Gas supply temporarily stopped, flue gas recirculation, incorrect earthing of product, ignition transformer has spark failure
F32 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, electronics defective
F49 eBUS fault: Voltage too low Short circuit on eBUS, eBUS overload or two power supplies with different polarities on the eBUS
F61 Fault: Gas valve control system Short circuit/short to earth in cable harness for the gas valve, gas valve defective (coils shorted to earth), electronics defective
F62 Fault: Gas valve switch-off control Delayed switch-off of gas valve, delayed extinguishing of flame signal, gas valve leaking, electronics defective
F63 Fault: EEPROM Electronics defective
F64 Fault: Electronics/sensor/analogue-todigital converter Flow or return NTC short circuited, electronics defective
F65 Fault: Electronics temperature too high Electronics overheating due to external influences, electronics defective
F67 Value sent back by ASIC is incorrect (flame signal) Implausible flame signal, electronics defective
F68 Fault: Unstable flame (analogue input) Air in gas, gas flow pressure too low, incorrect air ratio, incorrect gas restrictor, ionisation flow interruption (cable, electrode)
F70 Invalid product code (DSN) Display and PCB replaced at same time and Device Specific Number not reset, wrong or missing output range coding resistance
F71 Fault: Flow/return temperature sensor Flow temperature sensor signalling constant value: Flow temperature sensor incorrectly positioned on supply pipe, flow temperature sensor defective
F72 Fault: Deviation in the water pressure sensor/return temperature sensor Flow/return NTC temperature difference too great → flow and/or return temperature sensor defective
F73 Fault: Water pressure sensor not connected or has short-circuited Interruption/short circuit of water pressure sensor, interruption/short circuit to GND in supply line to water pressure sensor or water pressure sensor defective
F74 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
F75 Fault: Pressure sensor Pressure switch defective
F76 The safety cut-out in the primary heat exchanger is defective Safety cut-out feedback does not match the gas valve feedback
F77 Fault: Condensate or smoke No response, flue non-return flap defective
F.78 Interruption to DHW outlet sensor at external controller UK link box is connected, but hot water NTC not bridged
F83 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
F84 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
F85 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
F86 Fault: Underfloor heating contact Underfloor heating contact open, sensor disconnected or defective
F87 Fault: Electrodes Electrodes not connected or they are connected incorrectly, short circuit in the cable harness
F88 Fault: Gas valve Gas valve not connected or it is connected incorrectly, short circuit in the cable harness
F89 Fault: Pump Pump not connected or it is connected incorrectly, incorrect pump connected, short circuit in the cable harness
con No communication between the PCB and the user interface Electronics defective