This fault can involve incomplete combustion and carbon monoxide.
If anyone in the property feels sick, dizzy or drowsy, or you can smell gas: open the windows, leave the building, and do not switch anything on or off. Then call the National Gas Emergency Service.
0800 111 999Vokèra A11 fault codewhat it means and how to fix it
The appliance is detecting a flame when there should not be one. Turn it off at the fused spur and get a Gas Safe engineer out.
Stop — this needs an engineer
Get a Gas Safe registered engineer to look at your Vokèra A11
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What A11 means
A11 is a false flame, sometimes described as an extraneous flame signal. The control board is reading a flame signal at a point in the cycle when the gas valve is supposed to be shut and the burner extinguished. There are two possible explanations and they are not equally serious. The benign one is that the sensing circuit is faulty and reporting a flame that does not exist — a contaminated electrode, moisture across a connector, or a degraded amplifier on the board. The serious one is that the reading is accurate and gas is still burning after the valve was commanded closed, which means the gas valve is passing. That is a genuine gas safety fault. Because the appliance cannot tell you which of the two it is, and because you cannot tell from outside the casing either, the correct response is to treat it as the serious one until an engineer has proved otherwise. Do not keep resetting it to get heat.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Contaminated or shorting sensing electrode | Deposit or moisture provides a conduction path that mimics a flame signal. Benign in itself, and the more common of the two. | Common |
| Gas valve passing | The valve is not sealing fully when closed, so a small amount of gas continues to reach the burner. This is the reason the code is treated as urgent. | Occasional |
| Damp in the electrode lead or connector | Water tracking across a connector after a leak inside the case, or condensation in a cold garage installation. | Occasional |
| Control board flame amplifier fault | The board misreads its own input. Diagnosed once the gas side has been proved sound. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£110–£380
An electrode replacement is £110 to £190 fitted. A gas valve is £240 to £320. Expect a diagnostic charge on top if the two have to be separated with a flue gas analyser.
Typical UK prices including parts and labour, updated August 2026. Your quote may differ.
What other owners found
Nobody has shared what worked for them on this code yet. If you have had it, you would be the first — and it genuinely helps the next person.
Related Vokèra fault codes
- A01Get it checkedThe burner failed to light and the appliance has locked out. Check the gas supply and, in cold weather, the condensate pipe before calling anyone.Related: ignition and gas supply
- 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
- E01Get it checkedThe appliance tried to light and could not confirm a flame, so it has locked out. In winter a frozen condensate pipe is the most likely reason.Related: ignition and gas supply
- F.28Stop — call an engineerThe boiler tried to light and failed three times in a row, so it has shut the gas off and locked out. Do not keep resetting it.Related: ignition and gas supply
- 501Get it checkedNo flame was detected during ignition and the appliance has locked out. Check the gas supply and the condensate pipe before booking anyone.Related: ignition and gas supply
- L2Stop — call an engineerThe boiler failed to detect a flame during ignition and has locked out on the gas valve. Do not keep resetting it.Related: ignition and gas supply
Related guides
Common questions about Vokèra A11
The reset button is right there. Why should I not use it?
Because on a Vokèra the reset is easy to reach and this is the single code where reaching for it is the wrong move. Every other A code is asking to be reset once. This one is the appliance reporting a flame it cannot account for, and clearing that is the only thing you can do from the front panel that makes the situation worse. Isolate it electrically and leave it isolated.
I rent. What should I be doing today?
Report it to the landlord or agent in writing today rather than tomorrow, and use the words "the boiler is showing a false flame fault" so it is not triaged as a no-heating call. Landlords have a legal duty to maintain gas appliances. While you are writing, say whether the property has a working carbon monoxide alarm — in England, Scotland and Wales one is required in any room with a fuel-burning appliance, and if there is not one, that belongs in the same message.
My Vokèra shows E011 rather than A11. Is that the same fault?
Yes. Some Vokèra ranges label it E011 and describe it as an extraneous flame rather than a false flame. Same condition, same seriousness, same answer.
I am renting and my landlord says to just keep resetting it. Is that reasonable?
No, and you are entitled to push back. Gas appliances in rented property must be maintained by a Gas Safe registered engineer and checked annually. If you cannot get it dealt with, the Gas Safe Register and your local authority environmental health team can both advise.
How long can we go without heating while this is sorted?
Not indefinitely, but a night or two is a fair trade against the alternative. Use electric heaters in the meantime and keep pressing for the repair rather than accepting a reset as the fix.
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
- Trade body guidance
Checked by Technical reviewer (Gas Safe registration to be displayed on appointment) on 5 August 2026.