Boiler
EA 229
The EA 229 error code on a Worcester Bosch boiler indicates a flame supervision fault — the boiler is either failing to ignite or losing its flame shortly after lighting. This is a serious fault that prevents your boiler from running and requires prompt attention.
What does this error mean?
Your Worcester Bosch boiler uses an ionisation sensor to confirm a stable flame is present after ignition. When the EA 229 code appears, the boiler’s control board has detected that either no flame was established, or the flame dropped out unexpectedly during a heating or hot water cycle. The boiler will lock out as a safety measure to prevent unburned gas from accumulating.
Est. repair cost
£100–£200 for electrode replacement; £200–£350 for gas valve; diagnostic call-out £60–£100
🔍 Likely causes
🛠️ Step-by-step fix
Check your gas supply first: confirm other gas appliances (hob, gas fire) are working. If they aren’t, contact your gas supplier — do not attempt to investigate further yourself.
If on a prepayment meter, top it up and wait a few minutes for the supply to restore before retrying.
Press the reset button on your Worcester Bosch boiler (usually a flame symbol button) and hold for 3–5 seconds. Allow the boiler a full ignition attempt.
If the error returns immediately after reset, do not keep resetting repeatedly — more than two or three attempts without success risks flooding the heat exchanger with unburned gas.
Check that the boiler’s gas isolation valve (the lever on the gas pipe behind or beneath the boiler) is fully open — the handle should be parallel to the pipe.
If all of the above checks out and the fault persists, stop here. All further investigation — electrodes, gas valve, PCB — must be carried out by a Gas Safe registered engineer. This is a legal requirement in the UK.
📞 When to call a professional
Call a Gas Safe registered engineer if the boiler fails to light after one or two resets, if you smell gas at any point, or if the error code returns within a short period of normal use. When booking, tell the engineer you have an EA 229 lockout fault on a Worcester Bosch boiler — this points them directly to the flame supervision circuit and saves diagnostic time.
⚖️ Repair or replace?
Replacing an ignition or ionisation electrode typically costs £100–£200 including parts and labour; a gas valve replacement runs £200–£350. If your Worcester Bosch boiler is under 10 years old, repair is almost always the right call given the brand’s reliability and parts availability. For boilers over 12–15 years old, weigh the repair cost against a new A-rated Worcester Bosch boiler (typically £1,800–£2,800 installed), especially if this is not the first fault.