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Worcester Bosch EA Fault Code Explained
EA on a Worcester Bosch boiler is a flame-detection lockout: the boiler tried to fire but could not establish or detect a flame, so it shut itself down for safety. Here's what it means, the few things you can safely check, and when it's an engineer's job.
Quick answer
EA means your Worcester Bosch boiler could not detect a flame and has locked out as a safety measure. First, check your gas supply is on and other gas appliances work, and in cold weather check whether the external condensate pipe has frozen — if it has, you can thaw it. Then reset the boiler once.
If EA returns after a single reset, stop and call a Gas Safe registered engineer. A repeating EA usually points to a gas-supply, ignition electrode, flame-sensing or gas-valve fault that only a registered engineer may legally investigate.
What does EA mean on a Worcester Bosch boiler?
EA is a "lockout" fault on Worcester Bosch Greenstar boilers. It means the boiler attempted to ignite but the flame-sensing circuit did not pick up a stable flame — so the control board (PCB) shut the boiler down rather than keep letting gas through. This is a deliberate safety response, not a sign the boiler is dangerous in itself.
On boilers with a digital display you'll often see EA followed by a three-digit number that narrows down the cause. The two you're most likely to meet are EA 227 and EA 229.
EA 227 — no flame detected on ignition
EA 227 means the boiler tried to fire several times but never detected a flame (no "ionisation" current following ignition). The boiler then locks out. This points towards a problem getting gas to the burner, lighting it, or sensing it.
EA 229 — insufficient flame signal during operation
EA 229 means the boiler detected too weak a flame signal (low ionisation current) during the burning phase, so it shut down. In cold weather a very common trigger is a frozen or blocked condensate pipe, which backs up and disrupts safe operation. It can also be a gas-supply dip, a dirty flame-sensing electrode or a gas-valve fault.
Reset EA only once. If the boiler locks out again on EA after a single reset, do not keep resetting it. Repeated resets won't fix the underlying fault and a persistent flame-failure lockout needs a Gas Safe registered engineer.
Common causes of EA
- No gas, or a gas-supply interruption (empty prepayment meter, a service valve turned off, or a wider supply issue).
- A frozen or blocked external condensate pipe — a frequent cause of EA 229 in winter.
- A dirty, worn or misaligned ignition / flame-sensing electrode.
- A faulty gas valve that won't open or modulate correctly.
- A blocked flue or restricted air supply affecting combustion.
- Low gas pressure at the meter, or a PCB fault on older units.
How to fix EA: the safe homeowner steps
There are only a few things you can safely do yourself. None of them involve opening the boiler or touching any gas component.
- Check your gas is on. Make sure the gas service valve is open and other gas appliances (hob, gas fire) work. If you're on a prepayment meter, check there's credit.
- Check the condensate pipe in cold weather. If there's an external white plastic pipe and the weather is freezing, it may have frozen. You can thaw it by pouring warm (not boiling) water over the frozen section, or holding a covered hot-water bottle against it. Our frozen condensate pipe guide walks through this safely.
- Reset the boiler once. Press and hold the reset button for around 3–5 seconds. See how to reset a Worcester Bosch boiler if you're unsure which button it is, or the general how to reset your boiler guide.
If the boiler fires and stays running, the EA was likely a one-off (often a frozen pipe that has now cleared). If EA comes straight back, it's an engineer's job.
When to call a Gas Safe registered engineer
EA sits very close to the gas safety bright line. By law, only a Gas Safe Register engineer may work on the gas supply, burner, gas valve, electrodes, flue, sealed combustion circuit or PCB. It is illegal and dangerous for an unregistered person to attempt this work.
Call an engineer if EA returns after one reset, if other gas appliances aren't working, or if you smell gas. If you smell gas or suspect a gas leak, leave the property and call the National Gas Emergency line on 0800 111 999.
An engineer will typically check the gas-supply pressure, inspect and clean or replace the ignition and flame-sensing electrodes, test the gas valve, check the condensate route and flue, and confirm the PCB is reading the flame correctly. This is the same diagnostic path as a wider boiler lockout or a faulty gas valve.
Typical Worcester Bosch EA repair cost
Costs vary by region and by what's actually wrong. These are indicative 2026 UK ranges — a frozen condensate pipe you thaw yourself costs nothing.
| Job | Indicative 2026 cost |
|---|---|
| Engineer diagnostic / call-out | £70–£120 |
| Thaw / clear condensate pipe | £0 (DIY) – £120 |
| Ignition / flame-sensing electrode | £90–£180 |
| Gas valve replacement | £150–£320 |
| PCB (control board) replacement | £300–£500 |
For a wider view of what heating jobs cost, see our boiler repair costs guide.
Related Worcester Bosch codes
EA is one of several flame and ignition faults. If you're troubleshooting more than one issue, these help:
- Worcester error codes — the full list of what each code means.
- Worcester fault codes hub — common Worcester faults and fixes.
- Worcester boiler no hot water — if EA left you with cold water.
- Worcester boiler repair — what a repair visit involves.
Will boiler cover pay for an EA repair?
This is general information, not financial advice — it depends on your policy and the cause.
Most boiler-cover and home-emergency policies will send a Gas Safe engineer and cover the labour and parts for a genuine breakdown — so a failed electrode, gas valve or PCB behind an EA lockout is usually the kind of thing cover is designed for.
Pre-existing faults, lack of servicing, or simply thawing a frozen condensate pipe (which you can often do yourself for free) may not be claimable, and most policies have an excess. Always check your own policy wording for what's included.
If you're weighing it up, read what boiler cover includes and our honest take on is boiler cover worth it before you decide.
Is the EA fault code dangerous?
The lockout itself is a safety feature — the boiler has shut down rather than keep passing gas without a confirmed flame, which is the safe outcome. The underlying cause (a gas-valve, electrode or supply fault) does need fixing by a Gas Safe engineer, but the boiler locking out is protecting you.
If you ever smell gas, leave the property and call the National Gas Emergency line on 0800 111 999.
Can I fix EA myself?
Only the safe basics: check your gas is on, thaw a frozen external condensate pipe in cold weather, and reset the boiler once. Anything inside the boiler — the gas valve, electrodes, flue or PCB — is gas work that only a Gas Safe registered engineer may legally carry out.
Will EA clear on a reset?
Sometimes. If the cause was temporary — a frozen condensate pipe that has thawed, or a brief gas-supply dip — a single reset can clear it and the boiler stays running. If EA comes straight back after one reset, the fault is ongoing and needs an engineer. Don't keep resetting repeatedly.
How much does it cost to repair EA?
If it's just a frozen condensate pipe you thaw yourself, nothing. An engineer diagnostic is typically £70–£120, an electrode around £90–£180, a gas valve £150–£320, and a PCB £300–£500 in 2026. The exact figure depends on the actual fault and your area.
What's the difference between EA 227 and EA 229?
EA 227 means the boiler never detected a flame after trying to ignite (no ionisation following ignition). EA 229 means the flame signal was too weak during the burning phase, so the boiler shut down — in winter this is often a frozen or blocked condensate pipe. Both end in a flame-failure lockout.
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Compare boiler coverThis article is general information, not gas-safety or financial advice. Always have gas appliances checked and repaired by a Gas Safe registered engineer. In a gas emergency, call the National Gas Emergency line on 0800 111 999. Costs are indicative UK guides for 2026.