Vaillant F54 / F.54 Fault Code
Meaning: This fault code suggests there is a fault in the gas supply. Usually this fault is accompanied by with a F.28 or F.29 Fault code.
Cause: According to Vaillant, there is insufficient gas supply to operate the unit. Gas isolator may be close on boiler or elsewhere. Also gas flow pressure may be too low.
Vaillant F54 / F.54 Fault Code Repair
The first and most simplest to check would be if the gas stop cock is fully open at the meter, near the boiler and anywhere else there may be any additional stop cocks.
Next would be to check if the check valve is working as it should. Solenoid testing equipment and multimeters may be required. If found faulty a replacement gas valve would be required.
Vaillant F54 / F.54 Fault Code Statistical Fault rate
Following are the approx percentage probability of the cause of a fault.
38 % – Gas Valve
31 % – Gas supply fault
29 % – Other causes ie pcb etc