EA checks
| Step | Check | If yes | If no / next |
|---|---|---|---|
| 1 | Is a burner flame visible? | Go to step 5 (earth / condensate / electrode path). | Go to step 2. |
| 2 | Is the gas cock on? | Go to step 3. | Open the gas valve and reset for 3 seconds. |
| 3 | Air in the supply pipe? | Vent the supply, then reset. | Go to step 4. |
| 4 | Natural-gas working pressure (or LPG flow rate) correct? | Confirm the correct code plug is fitted, then reset. | Check pipework and the building regulator / cylinder. |
| 5+ | Earth, condensate trap, air/gas diaphragm, gas-valve coils, flue/CO2, ignition electrodes, 20-pin harness, PCB | Work through those checks in order. Reset for 3 seconds after each repair. | 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.