Code Meaning
Vaillant ecoTec exclusive Green iQ combi boiler error codes
F.00 Interruption: Flow sensor
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.01 Interruption: Return sensor
F.02 Interruption: DHW outlet sensor
F.03 Interruption: Cylinder sensor
F.10 Short circuit: Flow sensor
F.11 Short circuit: Return sensor
F.12 Short circuit: DHW outlet sensor
F.13 Short circuit: Cylinder sensor
F.20 Safety switch-off: Temperature limiter
F.22 Safety switch-off: Low water pressure
F.23Safety switch-off: Temp.spread too large
F.24Safety switch-off: Temp. incr. too fast
F.25Safety switch-off: Flue temp. too high
F.26Fault: Fuel valve not working
F.27Safety switch-off: Flame simulation
F.28Start-up failure: Ignit. unsuccessful
F.29Start-up failure: Ignit. unsuccessful
F.32Fault: FanF.33Pressure switch
F.35Fault: Air/flue gas duct
F.42Fault: Coding resistor
F.49Fault: eBUS
F.55Fault: CO sensor
F.56Safety switch-off: CO limit exceeded
F.57Fault: Measuring program
F.61Fault: Fuel valve actuation
F.62Fault: Fuel valve switch-off delay
F.63Fault: EEPROM
F.64Fault: Electronics/sensor
F.65Fault: Electronics temp.
F.67Fault: Electronics/flame
F.68Fault: Flame signal unstable
F.70Fault: Invalid Device Specific Number
F.71Fault: Flow sensor
F.72Fault: Flow/return sensor
F.73Fault: Water press. sensor
F.74Fault: Water press. sensor
F.75Fault: Pump/ water shortage
F.77Fault: Flue non-ret. valve/condens. pump
F.78Interrupt.: DHW outlet sensor on ext. contr.
F.80Fault: actoSTOR inlet sensor
F.81Fault: cylinder charging pump
F.82Fault: Ext. current anode
F.83 Fault: NTC temp. gradient
F.84Fault: NTC temp. diff. implausible
F.85Fault: NTCs fitted incorrectly
F.90Fault: Communication
F.94Fault: Vortex and differential pressure
LED actoSTOR module: actoSTOR electronics status
Communication fault: Communication fault