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Vaillant ecoTEC plus 637 VU boiler fault and error code advice

Have you developed a fault with your Vaillant ecoTEC plus 637 boiler? If so, call our 24 hour UK call centre today to book a breakdown repair today. MR Boiler Repairs are the UK’s leading boiler repair and service specialist, providing support for domestic, commercial and residential properties. Our low cost fixed price repair service will provide you with peace of mind and avoid any scary repair bills.

Are you experiencing a fault with your EcoTEC plus 624 boiler? Below you’ll find information on the fault codes for your boiler and the possible reasons for the fault you are experiencing.

Fault codes for the Vaillant EcoTEC plus 637 VU

F.00  Flow temperature sensor interruption
F.01 Return temperature sensor interruption
F.02  Interruption cylinder charging sensor actoSTOR only in combination with F.91
F.03  Interruption cylinder sensor actorSTOR 

only in combination with F.91
F.10 Flow NTC short circuit
F.11 Return NTC short circuit
F.12 Short circuit at cylinder charging sensor only in combination with F.91
F.13 VU/VUW boiler: Short circuit warm start sensor/cylinder sensor
VUW boiler with actoSTOR: Short circuit cylinder sensor only in combination with F.91
F.20 Safety switch-off: temperature limiter
F.22  Safety switch-off: low water pressure
F.23 Safety switch-off: Temperature difference too great
F.24 Safety switch-off: Temperature rise too fast
F.25 Safety switch-off: Flue gas temperature too high
F.26Fault: Gas valve without  

F.27 Safety switch-off: Flame simulation
F.28 Failure during start-up: ignition unsuccessful
F.29 Failure during operation: Re-ignition unsuccessful
F.32 Fan Fault
F.32 Air/flue gas duct fault
F.35 Air/flue gas fault
F.42 Coding resistor fault, could be in combination with F.70
F.49 eBUS fault
F.52 Mass flow sensor connection fault
F.53 Mass flow sensor fault
F.54 Gas pressure fault (in combination with F.28/F.29)
F.56 Mass flow sensor regulation
F.57 Fault during comfort safety mode
F.61Gas value  

F.62  Gas value switch-off delay
F.63 EEPROM error
F.64 lectronics/NTC fault
F.65 Electronics temperature fault
F.67 Electronics/flame fault
F.68 Unstable flame signal fault
F.70 Invalid device specific number (DSN)
F.71 Flow NTC fault
F.72 Flow/return NTC fault
F.73 Water pressure sensor signal in the wrong range (too low)
F.74 Water pressure sensor signal outside correct range (too high)
F.75 Fault, no pressure ch 

ange detection when starting pump
F.76 Overheating protection on primary heat exchanger has responded
F.77 Flue non-return flap/condensate pump fault
F.78 Interruption to DHW outlet sensor at external controller
F.83 Flow and/or return temperature sensor temperature change fault
F.84 Flow/return temperature sensor difference implausible
F.85 Flow and return temperature sensors incorrectly fitted
F.92 Coding resistor fault
F.93 Gas group fault


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