What the EA 229 code means
On most Greenstar models, EA is the flame detection fault, and the cause code tells you when the problem happened. Worcester's Greenstar i manual describes 229 as "loss of ionisation signal during operation", and the Greenstar 8000 Life manual describes it as the flame failing during burner operation. Both say the same thing: the boiler lit, ran for a while, and then stopped detecting a flame.
That timing is what separates EA 229 from EA 227. With EA 227 the boiler never proves a flame after ignition. With EA 229 it lights successfully, so the ignition side is working, and something changes while it is running. The boiler uses a small electrical signal through the flame, called ionisation, to confirm it is still lit. When that signal drops away, the gas is shut off straight away for safety.
It helps to note when the fault happens. If it only appears when a hot tap is running, in very cold weather, or when the cooker is on, write that down for the engineer.
Common causes of EA 229
Gas supply interrupted
If the gas supply stops or drops while the boiler is running, the flame goes out. A prepayment meter running out of credit is a common example, as is low gas pressure when several appliances run at once.
Frozen or blocked condensate pipe
Worcester lists checking that condensate is draining correctly. If the pipe freezes, water backs up inside the boiler and can disturb the burner, leading to flame loss.
Flame sensing electrode
The electrode that senses the flame can become dirty, worn or out of position over time, which weakens the signal.
Flue problems
A damaged, blocked or poorly positioned flue can let flue gases affect combustion, especially in strong wind.
Wiring or earthing faults
The ionisation signal is small, so a poor connection or earthing problem can make the boiler think the flame has gone. This kind of fault often seems random, which is why keeping a note of when it happens is so useful.
| Cause | Typical sign | Who fixes it |
|---|---|---|
| Prepayment credit run out | Hob also stops working | You, by topping up |
| Frozen condensate pipe | Freezing weather, gurgling from boiler | You, by thawing the pipe |
| Low gas pressure | Fault when other gas appliances are on | Gas Safe engineer or gas network |
| Worn or dirty flame sensing electrode | Fault gradually becomes more frequent | Gas Safe engineer |
| Flue or earthing fault | Worse in wind, or after electrical work | Gas Safe engineer |
Safe checks you can do yourself
- Check whether your hob or other gas appliances work. If they do not, the problem is the gas supply rather than the boiler.
- If you have a prepayment meter, check the credit and top up if needed.
- Check the gas isolation valve under the boiler is open, with the handle in line with the pipe.
- In cold weather, check the condensate pipe outside for ice. Thaw it with warm (not boiling) water or a hot water bottle, as our frozen condensate pipe guide explains.
- Check the fused spur and power supply, particularly if there has been recent electrical work.
- Press and hold reset as your manual describes. Stop after two or three attempts.
If you smell gas, do not press reset or use electrical switches. Turn off the gas at the meter if it is safe to do so, open doors and windows, leave the property and call the National Gas Emergency Service on 0800 111 999.
When to call a Gas Safe engineer
If your gas supply is fine, the condensate pipe is clear and EA 229 keeps returning, call a Gas Safe registered engineer. Worcester's manual directs engineers to check the condition and connections of the flame sensing probe and confirm that condensate is draining properly. Most engineers will also check the working gas pressure at the boiler, inspect the flue and test the earth.
When you book, give the full code and say whether your other gas appliances work, whether the fault began during cold weather and whether it lines up with windy days or with other appliances running. If there has been recent electrical work in the house, such as a new consumer unit, mention that too, because earthing problems introduced during other work can upset flame sensing.
Do not remove the casing, adjust the flue or clean the electrode yourself. Flue faults carry a risk of carbon monoxide, so make sure you have a working carbon monoxide alarm near the boiler.
Typical repair costs in the UK
If the cause was gas credit or a frozen pipe, there is no cost. If a repair is needed, these ranges are typical. Prices vary by region and engineer.
| Job | Typical UK cost |
|---|---|
| Engineer call-out and diagnosis | Typically £80 to £150 |
| Flame sensing electrode replacement | Typically £100 to £180 |
| Flue repair or adjustment | Typically £100 to £300 |
| Rerouting or insulating the condensate pipe | Typically £100 to £250 |
| Gas valve replacement | Typically £250 to £450 |
How to stop EA 229 coming back
Keep prepayment credit topped up in winter, when usage rises quickly. If your condensate pipe runs outside, ask an engineer about insulating or rerouting it. Keep the flue terminal clear of plants and bins. A yearly service is the best way to catch a worn electrode or flue problem early, and our boiler service cost guide explains what to expect. If you also have hot water problems, our no hot water guide may help.