Error E09

Safety precautions:

1) If you smell gas: leave the property immediately, do not operate switches or appliances, do not use phones inside, and call your gas emergency number and the gas supplier from a safe location.

2) Do not open the boiler or attempt to work on gas valves, internal PCB components, or mains wiring. Working on gas appliances is dangerous and illegal for unqualified people.

3) Isolate mains power to the boiler only if instructed below and only at the external isolator; do not attempt internal electrical repairs.

Initial homeowner checks you can do safely:

1) Try a timed reset: follow the boiler’s reset procedure (selector to R or press and hold reset button for 5–10 seconds) and note if the E09 returns immediately or after an attempt to ignite. Record any additional digits shown after the E09.

2) Check the boiler has mains power (external switch, fuse or circuit breaker) and the display is on.

3) Check the gas supply is available: confirm other gas appliances (hob, oven) work or that the meter/isolation valve is open and, if you have a prepayment meter, that there is credit.

4) Check external controls: programmer, room thermostat, and any wireless or wired thermostats are calling for heat and have working batteries where applicable.

5) Visually inspect any external wiring or terminal boxes you can see without removing covers (for example thermostat wiring terminals or external zone controller connections). If wires look burnt, loose or damaged, isolate power at the external isolator and call an engineer — do not touch or attempt repairs.

If E09 persists after the above and no gas smell is present:

1) Note the exact fault code wording and any sequence of codes and times — this information is useful to the engineer.

2) Do not attempt to force the boiler to run. Leave it switched off and arrange a Gas Safe registered engineer visit.

What a qualified engineer will do (for your information):

1) Perform safety checks and confirm gas supply and isolation before opening the boiler.

2) Visually inspect and re-seat all low-voltage connectors to the gas valve and PCB; check for corrosion, burnt pins or broken wires.

3) Measure the gas valve coil resistance and check the PCB output voltages/currents to the gas valve during an ignition attempt to confirm whether the valve or PCB is at fault.

4) Check continuity of wiring between PCB, connectors and any external controls; repair or replace damaged wiring looms or connectors as required.

5) If needed, replace the gas valve or PCB, reconfigure or calibrate the appliance, run combustion and safety checks, and confirm correct operation and flame sensing.

6) Complete a gas safety record and explain the repair and any follow-up recommendations.

Summary: try a safe reset and basic checks (power, gas supply, external controls). Do not open or repair the boiler yourself. E09 requires a Gas Safe registered engineer to diagnose and repair wiring, valve or PCB faults to ensure safe, legal and correct restoration of the appliance.