Worcester Bosch 2951 fault codewhat it means and how to fix it
The 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.
Stop — this needs an engineer
Get a Gas Safe registered engineer to look at your Worcester Bosch 2951
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.
When does it happen?
The right answer depends on what you can see. Pick the one that matches.
Choose the option on the left that matches what your appliance is doing, and the answer for that case appears here.
It comes on in windy weather and clears later
The flue terminal is the likely culprit — wind driving flue gas back or disturbing the air supply, which Worcester list as incorrectly sited flues and which also produces the 2948 and 2949 blocking codes.
Reset once with the up and down keys. Tell the engineer it is weather-related; that points them at the terminal before anything inside the case.
The boiler is newly installed or the gas supply was recently worked on
Incomplete purging of the gas pipe is on Worcester's list, and so is undersized pipework. Both are installation matters rather than boiler faults.
Call the installer who commissioned it rather than a general engineer; it is their commissioning to finish.
You can smell gas
Stop. This is an emergency, not a fault code.
Turn the gas off at the meter, open windows, do not operate switches, and call the National Gas Emergency Service on 0800 111 999.
What 2951 means
On the Greenstar 8000 Life, 8000 Style, 8000+, 4000 and 2000 the display shows a plain number, and 2951 is one of the locking faults: loss of flame too many times. It is the end of a sequence. Each time the burner is running and the flame goes out the boiler logs 229, flame failed during burner operation, which on these boilers is a blocking fault — it purges and tries again by itself.
When that happens repeatedly within a short spell the board stops trusting the process and locks out on 2951, and it will not run again until someone presses the up and down keys together. Worcester's remedy list is unusually candid about how wide the field is. It starts with a note that the combustion case cover being off can cause it, then says to refer to the blocking errors that led to the lockout in the fault history, then lists incomplete purging of a new gas pipe, and then a wide variety of issues such as undersized pipework or gas pressure dropping off, incorrectly routed condensate drains, incorrectly sited flues and incorrect wiring.
In other words the boiler is telling you it kept losing its flame, and the history menu tells the engineer under what conditions — at high output, in wind, when the hot tap ran. The 229 page on this site covers a single loss; this page is what happens when they add up. It is an ignition-family lockout and Worcester's own guide says to reset once and call if it returns.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Gas pressure falling under load | Worcester name undersized pipework and gas pressure dropping off. The flame is fine at low output and starves when the burner asks for more, which is why the history often shows the losses at full rate. | Common |
| Flue or condensate problem putting the flame out | Incorrectly sited flues and incorrectly routed condensate drains are on Worcester's list. Recirculating flue gas or a slug of condensate reaching the burner extinguishes it mid-run. | Common |
| Combustion case cover off or not sealed | The note at the top of Worcester's remedy. An unsealed case disturbs the air the burner is metering and the flame lifts off. | Occasional |
| Flame sensing or wiring fault | A weak ionisation signal reads as a lost flame even when it is burning. Incorrect wiring is the last item on the manufacturer's list. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£90–£480
Time on site
1h 30m
Diagnosis and a gas pressure test £90–£160. Electrode and lead £130–£220. Flue terminal re-siting or gas pipe upgrade is an installer's quote and can exceed £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
Worcester Bosch Greenstar gas valve
£180–£320Authorised Worcester parts distributor
Price checked 28 September 2026
Condensate trap and siphon
COND-TRAP£15–£38Plumbing merchant
Price checked 28 September 2026
Own this appliance and had this code? . Nothing is published until a person has read it.
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
- EA 229Get it checkedThe burner lit and then the flame was lost during operation. That is a different fault from failing to light in the first place.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
- 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
Common questions about Worcester Bosch 2951
How many times is too many?
Worcester do not publish the count on the boiler's own display; the manual only says loss of flame too many times and points the engineer at the history menu, which records the 229 events that led to it.
Can I keep resetting it?
No. Worcester's user guide says reset and call if it persists. On the 8000+ and 4000, five locking-fault resets inside fifteen minutes trigger the 2980 super lock-out, which only an engineer can clear.
Is 2951 the same as EA 229?
It is the lockout that follows repeated EA 229 events. On a Greenstar i the display would show EA 229 for each loss; on the 8000 generation you see 229 in the history and 2951 on the screen once the boiler has given up.
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.