EA Boiler Fault Code: What It Means on Every Brand

EA is an ignition-failure code on both brands that display it, but they are very different boilers. On Worcester Bosch — by far the more common — EA means the boiler tried to light (typically several attempts) and never proved a flame, and it usually comes with a three-digit sub-code such as EA 227 or EA 229 that narrows the cause. On Viessmann it carries the same broad meaning of repeated failed ignition. Either way, the first checks are gas supply, a frozen condensate pipe in cold weather, and one reset — then an engineer if it returns.

Lockout — engineer likely 2 brands use this code

Which brand is your boiler?

The brand is printed on the front casing. Tap your brand for the full causes, fixes and repair costs.

Brand	What EA means	Severity	DIY?
VViessmann	The EA fault code indicates that your Viessmann boiler has attempted to light its burner on multiple occasions and failed every time. Full guide →	Lockout — engineer likely	No
WBWorcester Bosch	EA on a Worcester Bosch boiler is an ignition lockout: the boiler tried to light its burner — typically up to four attempts — and could not confirm a stable flame on any of them, so it… Full guide →	Lockout — engineer likely	Some checks

EA brand by brand

Viessmann EA

The EA fault code indicates that your Viessmann boiler has attempted to light its burner on multiple occasions and failed every time. As a safety precaution, the boiler locks itself out and stops operating. This is not a fault to ignore — the boiler will not restart on its own until the underlying cause is identified and resolved. The code is most commonly seen on older Viessmann models such as the Vitocrossal 200 range, though it can also appear on the Vitodens series where it may relate to a missing or insufficiently strong flame signal at start-up.

Causes, fixes & costs for Viessmann EA → · All Viessmann codes

Worcester Bosch EA

EA on a Worcester Bosch boiler is an ignition lockout: the boiler tried to light its burner — typically up to four attempts — and could not confirm a stable flame on any of them, so it shut down rather than keep releasing gas it cannot light. It is the most common Worcester code by a distance, and on the Greenstar 4000, 8000 and CDi ranges it is almost always paired with a three-digit sub-code (EA 227, EA 229 and so on) that narrows the cause — EA 227 is 'never lit', EA 229 is 'lit, then lost the flame'. In winter the cause is usually outside the boiler: a frozen condensate pipe or an interrupted gas supply. Check those two, reset once, and if EA returns, book a Gas Safe registered engineer.

Causes, fixes & costs for Worcester Bosch EA → · All Worcester Bosch codes

Frequently asked questions

Is the EA fault code the same on every boiler?

Broadly, yes — on Viessmann and Worcester Bosch the EA code points to the same class of fault, and the recommended response is similar. Model-specific details such as sub-codes and reset procedures still vary, so follow the page for your own brand.

Can I fix a EA fault myself?

On some brands there are safe homeowner checks first — typically system pressure, the condensate pipe in cold weather, and a single reset. The underlying repair usually needs a registered engineer. Never open the boiler casing yourself.

Who should I call about a EA fault?

For gas boilers, a Gas Safe registered engineer — it is a legal requirement for any work on the appliance. If you smell gas at any point, leave the property and call the National Gas Emergency line on 0800 111 999.

General guidance only — not a substitute for professional advice, and not certified by a registered engineer. Any work on a gas appliance must be carried out by a Gas Safe registered engineer. If you smell gas, call 0800 111 999.