Indesit washing machine flashing 3 times
F03 / error 3 means the NTC thermistor (temperature sensor) has a fault or its wiring connections are faulty. Before replacing the NTC, check that all connections to the thermistor and the PCB are clean and secure. Test the NTC thermistor with a multimeter before ordering a replacement – a thermistor is inexpensive, but confirming the fault is there before spending is always worthwhile.
Error code 3 or F03 on an Indesit washing machine indicates a fault with the NTC thermistor (temperature sensor) or its connections to the main PCB. The machine is detecting that water temperature cannot be correctly monitored or controlled. This fault is identical to Hotpoint error F03 – the full diagnostic guidance applies to both brands.
How to Identify This Error Code
On Indesit machines that use a flashing light display rather than a digital readout, error 3 / F03 is shown as the On/Off indicator light flashing 3 times, pausing briefly, then flashing a further 3 times – repeating continuously. On machines with a digital display, F03 will appear directly on screen.
What the NTC Thermistor Is
The NTC (Negative Temperature Coefficient) thermistor is the temperature sensor in the washing machine. It monitors the water temperature during the wash cycle and reports it back to the main PCB. The PCB uses this reading to control the heating element – switching it on and off to reach and maintain the selected wash temperature.
If the thermistor fails, reads incorrectly, or loses its connection to the PCB, the machine cannot confirm that water is reaching the correct temperature. Depending on how the fault manifests, the machine may abort the programme and display F03 rather than risk running a cycle at the wrong temperature.
Diagnosis and What to Check
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Check the thermistor wiring connections.
The NTC thermistor sits on the heating element assembly at the base of the outer tub. It has two wires running from it to the PCB. With the machine unplugged, inspect the connector at the thermistor end and trace the wires back to the PCB connector. Disconnect and reconnect both ends to ensure a clean contact. A poor or corroded connection is a common cause of this error and is free to fix.
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Test the thermistor with a multimeter.
An NTC thermistor changes its resistance with temperature. At room temperature (approximately 20 degrees) a typical washing machine NTC should read around 6,000 to 10,000 ohms. In very hot water its resistance drops significantly. A reading of zero (short circuit) or infinite resistance (open circuit) confirms the thermistor has failed. See our full guide on how to test an NTC thermistor for the step-by-step process.
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Replace the NTC thermistor if confirmed faulty.
NTC thermistors are relatively inexpensive and straightforward to replace. Ensure the replacement is the correct type for the specific model. NTC sensors and thermostats for Indesit and Hotpoint washing machines are available at Spares4Appliances.
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If the error persists after replacing the NTC – consider the PCB.
If a confirmed working NTC is in place and the error continues, the fault may be in the PCB itself. PCB replacement is expensive and should only be considered after the thermistor and all wiring connections have been verified. An engineer with diagnostic equipment is recommended at this stage.
Indesit and Hotpoint washing machines share many components and control systems. Error F03 has the same meaning on both brands. See our guide on Hotpoint error code F03 for additional diagnostic context.
Need Parts or a Repair?
Related Guides
How to Test an NTC ThermistorStep-by-step guide to testing the NTC thermistor with a multimeter to confirm whether it has failed.
Hotpoint Error Code F03The same NTC fault on Hotpoint machines – identical diagnosis and repair applies to Indesit F03.
Washing Machine Not Heating WaterFull guide to heating faults including heater element, NTC, and PCB diagnosis.
Indesit Error Code F07Another Indesit heating system error – motor triac fault diagnosis.
Frequently Asked Questions
What does error code F03 mean on an Indesit washing machine?
F03 (also displayed as 3 flashes on machines without a digital display) means an NTC thermistor fault. The NTC is the temperature sensor that monitors water temperature during the wash cycle. The error indicates the machine cannot correctly read the water temperature – either because the thermistor has failed, its connections are faulty, or in rarer cases, the PCB has a fault.
Can I fix Indesit F03 myself?
Checking and reseating the wiring connections to the thermistor is a straightforward check that requires only unplugging the machine and locating the thermistor connector. Testing the thermistor with a multimeter and replacing it if confirmed faulty is also within reach for a confident DIY repairer. If the fault persists after replacing the thermistor, an engineer is recommended as the fault may be in the PCB.
Is Indesit F03 the same as Hotpoint F03?
Yes. Indesit and Hotpoint washing machines share the same underlying control systems and components through their common ownership under the Whirlpool group. Error F03 has the same meaning and the same diagnostic process on both brands.
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0 replies Just what I was looking for easy to understand explanation and very helpful, thank you
0 replies good explanation very useful
good explanation very useful
Just what I was looking for easy to understand explanation and very helpful, thank you