Smeg E9 fault codewhat it means and how to fix it
Smeg name the part outright: the inductor temperature sensor is defective. It is the sensor that makes the hob’s own over-temperature protection possible.
Take care
Get a qualified appliance engineer to look at your Smeg E9
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 has the hob been doing before E9 appeared?
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.
What has the hob been doing before E9 appeared?
Then this is not a new fault. It is Smeg’s own predicted end point for that symptom, and the control has now identified what was behind it.
Report both codes together and the order they appeared in. It makes for a shorter diagnosis and a better chance of the right part being on the van.
What has the hob been doing before E9 appeared?
A sensor or its connection can fail without warning, particularly in the hottest part of an appliance that heat cycles every day.
Book a visit with the model number and the affected zone to hand. There is no owner check that will tell you anything more.
What has the hob been doing before E9 appeared?
That localises it usefully. A single zone losing its temperature reading points at that inductor and its wiring rather than at anything shared across the hob.
Use the other zones if they behave normally, and say clearly which one is affected when you book.
What E9 means
Smeg publish E9 as a defective inductor temperature sensor, with an engineer needed if it persists. Compared with the rest of their table this is unusually direct. Most codes describe a symptom and leave the component to be found; this one names the part. That makes it a short page in one sense, because there is no diagnosis left to do, and an important one in another, because of what the named part is for. The inductor temperature sensor is how the hob knows how hot the coil assembly under the glass has become. Everything the appliance does to protect itself from heat depends on that reading. It is the sensor behind E2, the over-temperature code, and Smeg say so themselves in the E2 description: if the error persists after the cooking zone has cooled, the anomaly could be caused by the defective inductor sensor.
So E2 and E9 are two views of the same component. E2 is the hob acting on a temperature it believes; E9 is the hob concluding that the number it is being given cannot be believed at all. Reading them together is more useful than reading either alone. If your hob has been throwing over-temperature codes on cold zones and has now settled on E9, nothing new has broken. The control has simply worked out what was wrong. The reason this is not something to keep resetting past is the consequence rather than the code. A hob with no trustworthy temperature reading has lost the measurement its heat protection is built on, and the sensible thing for the firmware to do in that situation is refuse to run the zone rather than run it blind.
When a zone stops working, that is protection, not an additional fault. It is also worth saying that a sensor fault is not necessarily an expensive one in parts terms. Sensors are small components. What decides the bill is whether the sensor can be replaced on its own or whether it is part of the inductor assembly, which is a considerably larger item, and that varies by model. Smeg do not publish which applies to your appliance, so an engineer with the model number in front of them is the only reliable answer, and getting the exact code and the affected zone to them before the visit is the most useful thing you can do.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| The sensor itself has failed | The direct reading, and Smeg’s own wording. A temperature sensor that has drifted or gone open circuit reports a number the control cannot accept. | Common |
| A degraded sensor connection | The sensor sits in the hottest part of the appliance and its connection lives through every heat cycle, so the wiring fails as often as the part. | Occasional |
| Long-term heat stress on the assembly | Years of boiled-dry pans and sustained boost cooking age the components immediately beneath the glass faster than gentle use would. | Occasional |
| A measuring circuit fault on the board | The sensor is only half the measurement. If the circuit reading it has failed, the sensor is blameless and the board is the repair. | Occasional |
| An unresolved over-temperature history | Where a hob that had been showing E2 on cold zones tends to end up, because that symptom is Smeg’s own predictor of this diagnosis. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£120–£300
Time on site
1h 15m
A service visit plus the part. The sensor itself is small and cheap; the range reflects models where it is only supplied as part of the inductor assembly, which Smeg do not publish per model.
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 Smeg fault codes
- E6Get it checkedPower failure to the power board. Smeg publish a timed remedy rather than a flick of the switch: turn the appliance off for a full five minutes.Related: power board and electronics
- EAGet it checkedA power circuit board error on the induction hob. Rangemaster publish an EA too, describing something different, so check which brand’s table you are reading.Related: power board and electronics
- SHOUsually simple to fixNot a fault at all. The oven is in showroom mode, so the control panel works and no heating is possible. Smeg publish how to switch it off.Related: same brand
- U400Get it checkedSmeg publish six words for this: wrong connection, connect the equipment properly. On a hardwired range cooker that means an electrician rather than anything you can do.Related: same brand
- E2Get it checkedOverheating of the inductor on the hob, but E2 is also in Smeg’s pyrolytic oven list. Which display it is on changes the answer completely.Related: same brand
- Er03Usually simple to fixA knob or button is being read as held on. On these knob-operated range cookers that usually means a knob kept turned to A too long. Release it, then clean the hob as Smeg say.Related: same brand
Own a Smeg range cooker? Save it and its codes come first next time.
Related guides
Common questions about Smeg E9
How is this different from E2?
They are two views of one component. E2 is the hob acting on a temperature it trusts and stopping because that temperature is too high. E9 is the hob deciding the reading itself cannot be trusted. Smeg link them explicitly: their E2 description says that if the error persists after the zone has cooled, the cause could be the defective inductor sensor.
One zone has stopped working entirely. Is that a second fault?
Almost certainly not. Without a trustworthy temperature reading the firmware has no way to protect the coil assembly, and refusing to run the zone is the correct response to that. Treat the dead zone as a consequence of the code rather than as something extra to report, though do say which zone it is.
Is a sensor an expensive repair?
The part is usually small and inexpensive. The variable is whether it can be replaced on its own or only as part of the inductor assembly, which is a much larger item, and that differs between models. Smeg do not publish which applies to yours, so an engineer with your model number is the only reliable source for the figure.
Do Smeg’s two support pages agree about this one?
For once, yes. Their newer induction article gives E9 a meaning and says an engineer is needed, and their older article lists E/9 among the codes requiring an engineer. The two disagree in several other places, notably about Er03 and U400, so it is worth noting where they line 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 support portal
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.