Vaillant Combi Boiler Error Codes
Vaillant ecoTEC boilers display 'F.' fault codes on the digital display. Note the full code (including the number after the dot) before calling.
This is not a DIY repair
Combi boilers are gas-fired appliances regulated under the BC Safety Standards Act. Opening the unit, touching the gas valve, or working on the flue without a valid BC gas-fitter licence is both unsafe and illegal. Diagnosing the fault is helpful — fixing it should always be left to a certified technician.
Call 778-909-5731Vaillant fault codes (15)
F.22ModerateLow water pressure / dry fire protection.F.23UrgentTemperature spread too large (flow/return).F.24UrgentTemperature rise too fast — poor circulation.F.27UrgentFlame detected when gas valve closed (false flame).F.28UrgentFailure to ignite during start-up.F.29UrgentFlame lost during operation.F.32UrgentFan fault — speed outside permitted range.F.49ModerateeBUS voltage / wiring fault.F.61UrgentGas valve control fault.F.62UrgentGas valve shut-off delay fault.F.63ModerateEEPROM / control memory fault.F.64ModerateElectronics / sensor short circuit.F.65ModerateControl electronics over-temperature.F.75UrgentPressure not detected at pump start.F.85ModerateFlow/return sensors fitted on same pipe.