Worcester Bosch EA fault code: flame loss and ignition lockout

What we check first with an EA lockout

The ignition sequence expects the flame-sense electrode to register current within a few seconds of the gas valve opening. If it does not, the boiler locks out rather than pumping unburnt gas into the heat exchanger. Common causes are a dirty or cracked flame-sense electrode, a failed spark generator, a condensate blockage backing up into the trap, or a genuine gas supply issue such as a spent LPG cylinder or a partially closed emergency control valve.

An EA lockout — the facts that change the job

• Reset twice at most — repeated resets on an unproven flame are unsafe
• Check other gas appliances light; if none do, the supply is the suspect
• A frozen or blocked condensate trap can trigger EA in cold snaps
• Electrodes are a wear item and are usually replaced during a full service
• The boiler will not run heating or hot water while locked out

Questions we get asked

Can I keep resetting an EA fault?

No. Two attempts is the accepted limit. If it locks out again the boiler has failed to prove a flame and needs an engineer before further resets.

Is an EA lockout dangerous?

The lockout itself is the safety system working correctly. The risk comes from repeatedly forcing ignition attempts on a faulty appliance.

Extra detail on an EA lockout

In hillside villages around Radstock and the Chew Valley we see EA cluster after the first hard frost, because external condensate runs freeze before the boiler has had its annual service. Where a condensate pipe leaves the building, 32mm insulated pipe run at a decent fall is the fix, not a kettle of hot water every January.

Where we deal with this

• Peasedown St John (BA2) · 3 mi
• Paulton (BS39) · 3 mi
• Bruton (BA10) · 13 mi