Hotpoint F04 fault codewhat it means and how to fix it
The temperature sensor circuit has failed — open circuit or shorted. A cheap part, which makes this one of the better codes to get.
Take care
Get a qualified appliance engineer to look at your Hotpoint F04
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 F04 means
F04 is a thermostat fault, and Hotpoint are more precise underneath than the short name suggests: the thermistor circuit is not compliant, meaning either a break in continuity or a short circuit. Those are the two ways a sensor of this kind fails, and both are electrically obvious to a meter, which is why this code tends to be a quick diagnosis. The component is an NTC thermistor — a resistor whose resistance falls in a predictable way as it gets hotter.
The machine does not measure temperature directly; it measures resistance and converts it. So a thermistor that has gone open circuit reads as infinite resistance, which converts to an impossibly cold reading, and one that has shorted reads as no resistance, which converts to an impossibly hot one. Either way the machine is being told something it knows cannot be true, and rather than heat blindly it stops. That refusal is the sensible behaviour: a dishwasher that cannot read its own water temperature has no safe way to decide when to stop heating. This is worth separating from the code next to it in the list.
F08 is a temperature timeout, where the sensor is working and reporting honestly that the water is not getting hot. F04 is the sensor itself being unreadable. The distinction matters commercially, because a thermistor is one of the cheapest parts in the machine, while the heating element it is often confused with is one of the dearer ones.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Thermistor failed open circuit | The break Hotpoint describe. The sensor stops conducting entirely and the machine reads a temperature that cannot exist. | Common |
| Thermistor shorted | The other half of Hotpoint’s wording. Resistance collapses instead of rising, so the reading goes impossibly high rather than impossibly low. | Common |
| Connector corroded at the sensor | A damp cabinet and a low-current signal are a poor combination, and a green connector reads to the board exactly like a failed sensor. | Occasional |
| Wiring damaged between sensor and board | A chafed or trapped core in the loom. Cheaper than any board and easily missed if the sensor is swapped without testing the run. | Occasional |
| Control board input failed | The board no longer able to read a healthy sensor. Rare, and reached only after the sensor and its wiring have been proven good. | Rare |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£80–£160
Typically £80 to £150 fitted, and most of that is the call-out rather than the component. A thermistor itself is a few pounds as a part.
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 Hotpoint fault codes
- F10Get it checkedHeating element fault — and the page to read the safety notice on if your machine was built between 2005 and 2015.Related: heating and drying
- F08Get it checkedTemperature timeout on the two-digit system. Check the shape of your code first, because a single-digit F8 belongs to a different code set and is not about heat at all.Related: heating and drying
- F03Get it checkedDrain failure or timeout — one of only two codes Hotpoint invite you to look at yourself, and usually a blockage.Related: same brand
- F06Get it checkedWater fill timeout. The other code Hotpoint hand back to you, and their own checklist covers pressure as well as the tap.Related: same brand
- F01Stop — call an engineerAnti-flooding overflow. The one code in the Hotpoint list that offers no owner check at all — it goes straight to an engineer.Related: same brand
- F11Get it checkedWash pump failure. The dishes come out dirty because water is never reaching them with any force.Related: same brand
Own a Hotpoint dishwasher? Save it and its codes come first next time.
Related guides
Common questions about Hotpoint F04
How is this different from F08?
F04 is the sensor being unreadable; F08 is the sensor working and telling the machine the water never got hot within the hour allowed. One is an instrument fault, the other is a heating fault. They matter differently to your wallet, because a thermistor is cheap and a heating element is not.
Is a thermistor an expensive part?
No, and that is the good news here. It is one of the least expensive components in a dishwasher, so most of what you pay for this repair is the visit rather than the part. If you are being quoted as though it were an element, ask what is actually being replaced.
Can I check it myself?
Not without taking the machine apart, and the sensor is not reachable from inside the tub. Hotpoint route this one to an engineer and that is the right call — but it is a fast diagnosis for anyone with a meter, so the visit should be short.
Will it still wash if I ignore it?
Probably not usefully. The machine stops rather than heat without being able to read the temperature, so at best you get a cold cycle that will not shift grease and has sanitised nothing.
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.