AEG Burner will not stay alightwhat to check
The flame dies when you let go of the knob. AEG give two causes and only one is yours: a dirty or misplaced burner cap, or a failed thermocouple.
Take care
What this means
This is the gas hob complaint, and AEG document it more usefully than most because they name both causes and draw the line between them. The symptom is precise: the burner flame goes out after you have let go of the control knob. What is behind it is the flame supervision device, which is a safety component doing exactly what it exists to do. A small probe sits in the flame and generates a tiny current while it is hot; that current holds a gas valve open. Take the flame away and the current stops and the valve shuts, which is why a gas hob does not quietly fill your kitchen when a pan boils over and puts a burner out.
AEG give two causes. The burner cap or crown are not placed correctly or are blocked with debris or water, which is yours. Or the thermocouple has failed, which is not. The owner-permissible remedy is worth following exactly, because the technique matters and most people get one part of it wrong. Push the knob down and turn it counter-clockwise to maximum, not minimum — a small flame may not heat the probe enough to hold the valve. Keep the knob pushed in for at least ten seconds, which is longer than instinct suggests. And check the cap and crown are correctly positioned, clean, and completely dry, because a cap sitting a few millimetres out of place puts the flame in the wrong position relative to the probe.
If that does not fix it, AEG recommend a service visit, and that is the correct boundary. In Great Britain the work behind the surface of a gas hob is restricted to Gas Safe registered engineers under the Gas Safety (Installation and Use) Regulations 1998, and no manufacturer in this research offers an owner any step beyond cleaning and repositioning.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| The burner cap or crown is out of position | AEG’s first stated cause and the commonest by a distance. A cap that has been put back slightly off after cleaning changes where the flame sits relative to the safety probe. | Common |
| Debris or water in the burner | A boil-over that has dried in the crown, or water left in it after cleaning, will both disrupt the flame pattern. AEG name both. | Common |
| The thermocouple has failed | AEG’s second stated cause. The probe no longer generates enough current to hold the valve open, so the burner cannot stay lit however long you hold the knob. Not an owner repair. | Occasional |
What to try yourself
Lift the burner cap and crown off and look at them. They should be clean, dry and seated so that they sit level and square on the burner base.
Clean them and dry them completely. AEG say completely dry, and mean it — water in the crown will keep this happening. For the metal probe itself AEG’s method on their electronic gas hobs is a moist soft cloth or sponge only.
Put them back carefully, making sure the cap is fully home rather than resting slightly proud on one side.
Light the burner with the knob pushed down and turned counter-clockwise to maximum, not to a low setting. AEG specify maximum for this.
Keep the knob pushed in for at least ten seconds after it lights, then release it slowly. This is longer than most people hold it and it is the step that usually makes the difference.
If it still goes out, stop and book a Gas Safe registered engineer. The thermocouple is the other cause and it is not owner-serviceable.
Do not try to clean, bend or adjust the probe next to the burner, and do not attempt to hold the valve open by any other means. If you can smell gas, do not touch any switch — leave the property and ring the gas emergency line from outside.
Get a qualified appliance engineer to look at your AEG hob
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£80–£180
Time on site
45 minutes
A Gas Safe engineer’s visit and a thermocouple, which is an inexpensive part with an access cost attached. Nothing at all if the cap was simply out of position.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related AEG fault codes
- F gas hobGet it checkedOn an electronic gas hob, F or E6 means a burner could not be ignited. AEG publish a reset sequence with a three-second window, and two different versions of it.Related: gas and ignition
- FUsually simple to fixOn an induction hob this is about the pan, and AEG say whether it is steady or flashing changes the answer. Steady on a new hob means the installation.Related: same brand
- E4Usually simple to fixOverheating protection operating, not a breakdown. It clears itself as the hob cools, and AEG warn that the residual heat H may stay on afterwards.Related: same brand
- E3Get it checkedThe hob is seeing 400 volts. AEG name the person to ring and it is not their service line — it is the qualified electrician who installed it.Related: same brand
- LUsually simple to fixThe panel is locked, and AEG publish two different locks that both show L. One re-arms itself every time you switch off, which is why hobs seem to lock themselves.Related: same brand
- E8Get it checkedAsk one question first: has this hob ever worked? A new install means a missing phase in the wiring. A hob that worked and stopped means the electronics.Related: same brand
Own an AEG hob? Save it and its codes come first next time.
Related guides
Common questions
Why maximum rather than a low flame?
Because the safety probe has to get hot enough to generate the current that holds the gas valve open, and a small flame may not do it. AEG specify turning the knob counter-clockwise to maximum when lighting, and holding it there for at least ten seconds.
Is a pilot flame around the probe a problem?
No, and AEG publish it as a correct-behaviour note precisely because people assume it is a leak. The flame that surrounds the thermocouple is a pilot flame that prevents unexpected shutdowns, and its presence does not indicate any appliance malfunction.
Can I replace the thermocouple myself?
No. Work on a gas appliance in Great Britain is restricted to Gas Safe registered engineers under the Gas Safety (Installation and Use) Regulations 1998, and AEG offer no owner step beyond cleaning and repositioning the cap and crown.
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 support portal
- Trade body guidance
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.