What the symbols on your oven mean
There is no international standard for oven symbols, which is why the same icon means different things on different makes. The shapes still follow a logic worth knowing.
What it usually means
Start with the fact that explains most of the confusion: oven symbols are not standardised. Laundry care symbols are — they come from an international standard and mean the same thing on a label sewn in Vietnam and a machine built in Turkey. Oven function symbols have no such agreement behind them, so each manufacturer draws its own, and an icon you learned on your last cooker can mean something different on this one. The manual for your specific model is the authority, and where a symbol here disagrees with it, the manual wins.
Within that, the shapes do follow a logic, and it is a physical one: the symbol is a little diagram of where the heat is coming from inside the box. A line across the top of a square means the upper element. A line across the bottom means the lower one. Both lines together means both, which is conventional or static heat and the setting that browns the top of a pie while cooking its base. A fan blade in the middle means the air is being circulated, and a fan with lines above and below means circulated air plus elements, which is what most people mean by a fan oven. A fan on its own, with no lines, is moving air without heating it, which is a defrost setting rather than a cooking one. A zigzag along the top is the grill, and a zigzag with a fan under it is a fan-assisted grill that cooks a thicker piece of meat through rather than only searing its surface.
The second group is the one people actually search for, and they are not functions at all. They are states. A padlock is a lock — but on a pyrolytic oven it may be the door lock engaged during a clean rather than the child lock, and those clear in completely different ways. A word like Demo or small squares on the display means the appliance is in shop mode and will never heat. SAFE or Loc means the controls are frozen deliberately. A flashing clock is an interlock on many ovens rather than a nuisance. None of these is a fault, and all of them are routinely mistaken for one.
The third group is genuine faults, and they look different: a letter and a number, usually F or E, sometimes with a longer string after it. If what you are looking at is a code rather than a picture, it belongs on the page for that code, where the specific meaning your manufacturer publishes for it is written out.
How to narrow it down
Work through these in order.
Is it a fan blade inside a circle?
A fan with a line above and below it is fan-assisted cooking: circulated air plus the elements, the setting most recipes assume when they tell you to drop twenty degrees. A fan with no lines at all is air circulation without heat, which is a defrost or resting function and will never cook anything.
Is it lines at the top, the bottom, or both?
These are pictures of which element is on. Both lines is static or conventional heat, good for cakes and pastry. Bottom only puts heat under the tin and is what you want for a pizza base or a quiche. Top only is for browning something already cooked, and it will not cook anything through on its own.
Is it a zigzag line?
That is the grill. A zigzag spanning the full width is the whole grill element, and a shorter one across half is a half grill for cooking two pieces rather than six, which saves electricity. A zigzag combined with a fan is a fan grill: hot air moving over the food as well as radiant heat above it.
Is it a padlock?
Two quite different things wear this symbol. The child lock, which you switch off by holding the lock key for a few seconds. Or, on a pyrolytic oven, the door lock that engages for a self-clean cycle and will not release until the cavity has cooled, which can take well over an hour and cannot be hurried.
Is it a word rather than a picture?
Demo, SAFE, Loc, PYR, ECO and a handful of others are settings and reminders, not failures. The one that catches most people is demo or shop mode: the oven lights up, accepts a temperature, runs its fan and never gets warm, which looks exactly like a dead element and costs nothing to undo.
Is it a letter followed by numbers?
Then it is a fault code rather than a symbol, and it is worth looking up precisely because manufacturers publish wildly different amounts about them. Some codes have a named part and a procedure behind them; others have nothing at all, and knowing which you are dealing with is what stops you paying for a guess.
Is the symbol on a knob rather than a screen?
On a dial-controlled oven the symbols are engraved round the function knob and there is no display to explain them, so the manual is the only reference. If you no longer have it, the model number is on a plate on the door frame, visible with the door open, and every manufacturer publishes manuals against it.
Codes commonly shown with this
- DemoAEGThe oven lights up, accepts settings and never heats. AEG admit demo mode can switch itself on after a power cut, and the code to switch it off is 2 4 6 8.Usually simple to fix
- SAFEAEGSAFE or a padlock symbol means one of three things on an AEG oven, and only one of them needs you to do anything. Work out which before you start pressing buttons.Usually simple to fix
- PYRAEGA reminder to run a self-clean, not a fault. The important part: the oven is counting hours rather than detecting dirt, so a spotless oven will still ask.Usually simple to fix
- LOCBoschBosch UK say the child lock shows LOC. None of their own manuals says that — six of them describe a key symbol or SAFE, and none mentions LOC at all.Usually simple to fix
- KeylockHotpointNone of the buttons work. Hold the lock key for at least five seconds to release it — the oven is not broken, the panel is locked.Usually simple to fix
- Small squaresNeffSmall squares on the display mean demo mode was switched on by accident. Neff describe what that does in five words: in demo mode the oven runs cold.Usually simple to fix
When it is urgent
Take care
What it costs
Typical repair cost
£0–£220
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Get an engineer to look at this
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.
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.