Worcester Bosch EA 229 fault codewhat it means and how to fix it
The burner lit and then the flame was lost during operation. That is a different fault from failing to light in the first place.
Take care
What EA 229 means
EA 229 is worth separating carefully from EA 227, because the two get treated as the same thing and they are not. EA 227 means no ionisation was detected after ignition — the burner never established a flame. EA 229 means an established flame was subsequently extinguished, or that ionisation was lost during the burning phase. So on an EA 229 the electrode sparked properly, gas arrived, the valve opened and combustion started.
Something then interrupted it. That rules out a good deal and points at a shorter list: a gas supply that sags under load rather than being absent, condensate backing up once the appliance starts producing it, or disturbance at the flue. Worcester's own literature mentions a blocked sump and strong wind into the flue as causes, and both are worth taking seriously. Wind in particular is under-appreciated — an exposed terminal on a gable end can genuinely blow a flame out, and the fault will track the weather rather than the clock.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Condensate sump or trap blocked | Worcester name a blocked sump directly. Condensate backs up into the combustion chamber shortly after firing, which is why the appliance runs for a consistent short period each time before dropping out. | Common |
| Gas supply inadequate under full rate | Enough to light, not enough to sustain. Typically worse when a hob or another gas appliance is running simultaneously. | Common |
| Wind into the flue terminal | Named in Worcester's documentation. An exposed terminal on a gable or in a wind funnel between buildings can disturb combustion enough to lose the flame. Suspect it if the fault follows the weather. | Occasional |
| Flame sensing electrode losing signal when hot | A marginal electrode reads adequately from cold and falls below threshold as the chamber heats and components expand. | Occasional |
What to try yourself
Time it over two or three attempts. Note how long the appliance runs before the code appears. A consistent interval points at condensate; an erratic one points at gas supply or wind.
Check whether it fails sooner with a gas hob running at full rate. If so, the supply is the likely constraint and needs an engineer with a manometer.
Note whether it is noticeably worse on windy days. Only you can observe that over time and it is genuinely valuable to whoever attends.
In cold weather, check the external condensate pipe for ice and thaw it with hand-hot water if you find any.
Never use boiling water or any form of heat gun on a condensate pipe. Cold plastic cracks readily.Reset no more than twice, and give the engineer your timing observations. It will very likely save a return visit.
Get a Gas Safe registered engineer to look at your Worcester Bosch EA 229
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£90–£450
Time on site
25 minutes
Clearing a blocked sump or condensate trap is £90 to £170. An electrode is £120 to £200 fitted. A flue modification for wind exposure is £180 to £400.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Worcester Bosch Greenstar electrode set
87161431020£22–£52Authorised Worcester parts distributor
Price checked 28 September 2026
Condensate trap and siphon
COND-TRAP£15–£38Plumbing merchant
Price checked 28 September 2026
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Related Worcester Bosch fault codes
- EA 227Stop — call an engineerThe boiler tried to light and never detected a flame, so it has shut the gas off and locked out. This is the most common Worcester fault code.Related: ignition and gas supply
- F7 228Stop — call an engineerA flame is being detected before the burner has started. Switch the appliance off and get a Gas Safe engineer rather than resetting.Related: ignition and gas supply
- FA 306Stop — call an engineerThe boiler detected a flame after it had closed the gas valve. That points to a valve letting gas past when it should be shut, and it must not be reset.Related: ignition and gas supply
- 2951Stop — call an engineerThe flame has been lost too many times in a row and the boiler has locked out. Each loss was a 229; Worcester's instruction is to read the history and find what put it out.Related: ignition and gas supply
- EA 261Stop — call an engineerAn ignition fault that Worcester define two ways: on the Greenstar i it points at the heat control module, on the Compact range it means the flame was not established inside the four-second ignition window.Related: ignition and gas supply
- EA 234Get it checkedThe control board cannot see the gas valve coil, so it will not attempt to light. Worcester call it a gas valve error, coil disconnected. No gas is released, but it is a gas job.Related: ignition and gas supply
Own a Worcester Bosch boiler? Save it and its codes come first next time.
Related guides
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.