Vaillant Boiler Error Codes

Vaillant EcoTEC Pro, EcoFIT Pure & EcoTEC Plus Boiler Error Codes

Vaillant’s award-winning combination, system and open vent boilers are renowned for their reliability, performance and efficiency.

Sometimes things can go wrong, so we’ve created a handy table of Vaillant boiler error codes below.

F – Fault CodePossible Cause
F.0/F.00Flow temperature sensor interruption
F1./F.01Return temperature sensor interruption
F.10Flow NTC short circuit
F.11Return NTC short circuit
F.20Safety switch off temperature limiter
F.22Safety switch off low water pressure
F.23Safety switch off temperature difference too great
F.24Safety switch off temperature is rising to fast
F.25Safety switch off flue gas temperature too high
F.26Error with gas valve – possible no function
F.27Safety switch off flame simulation
F.28Failure during start up – ignition unsuccessful to start
F.29Failure during operation – re-ignition unsuccessful
F.32Fan error
F.49eBUS error – possible short circuit
F.61– Error with gas valve regulation
F.62Error with gas valve – switch off delay
F.63EEPROM error
F.64Electronics / NTC error
F.65Electronic temperature error could be overheating due to external influences
F.67Electronics flame signal error
F.68Unstable flame signal error air in gas
F.70Invalid device specific number (DSN)
F.71Flow NTC error – flow temperature sensor signal constant value
F.72Flow return NTC error – temperature difference too great
F.73Water pressure sensor signal in the wrong range, it is too low
F.74Water pressure sensor signal outside correct range, the sensor signal is too high
F.75Error with pressure – no pressure change detection when starting the pump
F.76Overheating protection on – primary heat exchanger has responded
F.77Flue non return flap condensate pump error
F.78Interruption to DHW outlet sensor at external controller
F.83Flow and or return temperature sensor error
F.84Error with flow/return temperature sensor temperature changing error
F.85Error with flow and return temperature, sensor incorrectly fitted
CONNECTIONNo communication with the PCB
S – Fault CodePossible Cause
S.00Heating mode error – no heat demand
S.01Heating mode fan start-up
S.02Heating mode error – water pump running
S.03Heating mode – ignition sequence error
S.04Heating mode – burner ignited
S.06– Heating mode – fan overrun error/td>
S.07Heating mode – pump overrun error
S.08Heating remaining cut off time xx minutes
S.10Hot water demand via impeller sensor
S.11DHW mode fan start up error
S.13DHW mode ignition error
S.14Hot water demand via fan sensor error
S.15DHW mode pump and fan overrun
S.16DHW mode – fan overrun error
S.17DHW mode – pump overrun error
S.20DHW mode – burner on error
S.21DHW mode – fan start up error
S.22DHW demand – error pump running
S.23DHW ignition error
S.24DHW mode – burner error
S.25DHW mode – pump or fan overrun error
S.26DHW mode – fan overrun
S.27DHW mode – pump overrun
S.28Hot water burner anti-cycling time
S.30Room thermostat is blocking heating mode
S.31No heat demand boiler in summer operating mode
S.32Waiting period because of fan speed deviation
S.34Heating mode frost protection error
S.39/td>Burner off contact has been triggered this could be because of contact thermostat or condensate pump
S.40Comfort safety mode active
S.41Water pressure > 2.8 bar
S.42Flue non return flap return signal blocks burner operation
S.46Comfort safety mode flame loss at minimum load
S.53Boiler is in waiting period of modulation f block function due to water shortage
S.54Boiler is in waiting period of operation, blocking function as a result
S.57Waiting period comfort safety mode
S.58Modulation limitation due to noise / wind error
S.61Gas family check unsuccessful

Vaillant Eco Tec Plus
Get a Boiler Quotation in 60 seconds

  • No delays! Get your Boiler quote immediately

  • Experienced Boiler Engineers

  • Hassle FREE Boiler Installation

Warm Home
Baxi 400 heat Boiler

Vaillant Eco Fit Pure
Fully Installed From
£1,940 INC VAT

10 Year Parts & Labour Guarantee

Warm Home Plus
Baxi 600 Combi Boiler
Vaillant Eco Tec Plus

Fully Installed From
£2,125 INC VAT

8-10 Year Parts & Labour Guarantee

The Landlord Package
Baxi 600 Combi Boiler
Main Eco Compact
Fully Installed From
£1,750 INC VAT

5 Year Parts & Labour Guarantee

Fixed Price Boiler Installations in 48hrs

5 Star Experience
Up to 10 years Guarantee

Boiler finance - Installation from £1750
Boiler in a kitchen