Smarter Heating & Hot Water

Worcester Bosch FA Fault Code

FA, the reset button, and the fault indicator LED are flashing. Flame is detected after the appliance switches off.

Fault codes / Worcester Bosch

FA checks

StepCheckIf yesIf no / next
1Condensate trap blocked?Clean the trap and discharge, then reset.Go to step 2.
2Electrode assembly burnt out?Replace electrodes and reset.Go to step 3.
3CO2 in combustion air above 0.2%?Check and clean the flue, then reset.Go to step 4.
4Gas valve damaged?Isolate gas and power, replace the valve, leak-test, reset.Go to step 5.
520-pin connector lead damaged?Replace the harness, then reset.Replace the PCB last, restoring service settings.

Gas work stays with a Gas Safe registered engineer. These steps are guidance from the manufacturer sequence, not a substitute for the handbook.