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boiler service, boiler repair, emergency repair
Vaillant Ecotec plus 438 Boiler Fault Codes
| Code | Meaning | Cause |
| F0 | Flow–NTC open circuit | NTC broken, NTC cable broken, Defective connection at NTC, Defective connection at electronics |
| F1 | Return–NTC open circuit | NTC broken, NTC cable broken, Defective connection at NTC, Defective connection at electronics |
| F10 | Flow NTC short circuit | NTC defective, short circuit in cable harness, cable/casing short cut |
| F11 | Return NTC short circuit | NTC defective, short circuit in cable harness, cable/casing short cut |
| F13 | Tank NTC short circuit | NTC defective, short circuit in cable harness, cable/casing short cut |
| F20 | Safety temperature limiter by NTC activated | Flow-NTC not correctly thermal-connected or defective; appliance does not shut down |
| F22 | Dry fire | Too little water in the appliance, water pressure sensor defective, cable to pump or water sensor defective, pump blocked or defective, pump output too low |
| F23 | Water shortage, temperature difference between flow and return NTC too large | Pump blocked or defective, pump output too low, flow and return NTC interchanged |
| F24 | Water shortage, temperature rise too quick | Pump blocked, insufficient pump output, air in appliance, water pressure too low |
| F27 | Incorrect sensing of flame | Flame detector defective |
| F28 | Appliance does not start: Attempts to ignite during start failed | Faults in the gas supply such as:- - Gas meter or gas pressure detector defective - Air in gas- Gas flow pressure too low - Fire protection tap has disengaged Faults in the gas valve, wrong gas setting, igniter (ignition transformer, ignition cable, ignition plug) defective, ionisation current stopped (cable, electrode), faulty earthing in appliance, electronics defective |
| F29 | Flame goes off during operation and subsequent | Ignition attempts failed Gas supply temporarily stopped, faulty earthing of appliance |
| F32 | Fan speed variation | Fan blocked, plug not inserted correctly on fan, hall sensor defective, fault in cable harness, electronics defective |
| F49 | eBUS under voltage | Short circuit on eBUS, overload on eBUS or two power sources on eBUS with different polarity |
| F61 | Gas–valve control defective | Short circuit/earth (ground) leak in cable harness to gas valves, gas valve assembly defective (earth/ground leak from coils), electronic control system defective |
| F62 | Gas valve shut off delay | Gas valve leaking, electronics defective |
| F63 | EEPROM error | Electronics defective |
| F64 | Electronics/NTC fault | Short-circuit in flow or return NTC or electronics defective |
| F65 | Electronics temperature too high | Electronics too hot due to external effect, electronics defective |
| F67 | Flame detector input signal is outside the limits (0 or 5 V) | Electronics defective |
| F70 | No valid DSN in display and/or main board | Spare part failure display and main board interchanged at same time and device specific number not adjusted |
| F71 | Flow NTC reports constant value (stuck at) | Flow NTC is defective |
| F72 | Flow and/or return NTC fault | Flow and/or return NTC is defective (tolerances too big) |
| F75 | No pressure rise was detected on turning on the pump | Water pressure sensor or/and pump defective Air in the heating system, quick bleeder defective Too little water in appliance; check adjustable by-pass; connect external expansion vessel to return |
| F76 | Overheating protection on primary heat exchanger triggered | Cable or cable connection of fuse in the primary heat exchanger defective, or primary heat exchanger defective |
| F77 | Condensate pump or feedback of accessories blocks heating | Condensate pump defective or flume flap feedback triggered |
| F78 | Wrong configuration with accessory | link box VR65 connected to combination boiler |
| con | No communication to main board | Connection error display main board |