Boiler Breakdown Fault Codes
Where to find them, What are they for and their limitations​.
Search your fault code type make and model of your boiler and add the fault code without spaces; E.g. Vaillant Ecotec f22 (rather than f 22)
Faults codes are not definitive, they are trigger by specific sensors or differences between sensors for example if the flow temperature sensor is overly divergent from a return temperature sensor this would trigger a fault code. Faults codes are they indication of fault are a guidline for example a certain fault code might indicate accroding to manufactureres instructions that a fan has failed as the boilers princted circuot borad does not recieve information (a complete circuit) from an air pressure switch installed as a safety device to monitor the fan. However if the safety device itself were to fail the same fault code would appear. A professional gas engineer would never chnage a part based on a fault code but would use ithe fault code to aid investigation of faults.