Worcester Bosch EA 229 Fault: No Flame — Causes & What To Do

EA 229 indicates the boiler's ionisation signal — the small electrical current that confirms the burner flame is present — was insufficient or lost. The boiler locks out because it can't safely confirm a flame. You'll usually have no heating and no hot water.

The most common causes, in order of how often we see them on call-outs:

• • Frozen condensate pipe — in cold weather the condensate discharge pipe outside can freeze, blocking the flue and preventing ignition. EA 229 (sometimes shown with D5) is the classic frozen-condensate code on a Worcester Bosch.
• • No gas supply — the gas valve at the meter or boiler may be off, a prepayment meter may have run out, or the supply may be interrupted. Check other gas appliances first.
• • Faulty ionisation or flame electrode — the electrode that detects the flame can wear or scale up, so the boiler can't confirm the flame even when it's lit.
• • Flue blockage or draft — a blocked or restricted flue can prevent the burner establishing a stable flame.
• • Gas valve fault — the gas valve may not open correctly, so there's nothing to ignite.

You can try one reset after checking the gas supply and (in winter) the condensate pipe. If the condensate is frozen, thawing it and resetting can clear EA 229. If gas supply is fine and the condensate isn't frozen, a reset won't help — the ionisation electrode, gas valve or flue needs a Gas Safe engineer.

• • Check other gas appliances — if your hob or gas fire also won't light, the issue is your gas supply (meter, prepayment credit, or a supply fault), not the boiler. Contact your gas supplier.
• • Check the condensate pipe outside — in freezing weather, look for ice at the pipe end or where it dips. If frozen, warm it gently with a hot water bottle or warm (not boiling) water poured over the frozen section, then reset the boiler.
• • Check the pressure gauge — if it's below 0.6 bar, repressurise to 1.2 bar via the filling loop, then reset.
• • If gas supply is fine, the condensate isn't frozen, and pressure is normal, the fault is the ionisation electrode, gas valve or flue — book a Gas Safe engineer. Don't keep resetting.

The ionisation electrode, gas valve and flue connections sit inside or on the boiler casing and involve gas. Any work inside the casing is gas work that must be done by a Gas Safe Registered engineer. Never open the boiler casing yourself.

• • Test the ionisation current — whether the boiler reliably detects the flame.
• • Inspect and clean or replace the ionisation/flame electrode.
• • Confirm gas supply and pressure at the boiler.
• • Check the condensate route and flue for blockages or restrictions.
• • Test the gas valve opens and lets gas through correctly.
• • Diagnose the PCB flame signal, replace the faulty part, and re-commission with a combustion check.

Our Gas Safe Registered (594547) engineers repair every Worcester Bosch model — Greenstar CDi, Si, Ri and 8000 — across Surrey, Berkshire, Buckinghamshire and West London, and carry common sensors, fans and ignition parts on the van. Most Worcester Bosch fault-code repairs are completed in a single visit, with any part quoted and agreed before fitting.