The F03 error on your Indesit Washing means the machine has detected a fault with the water temperature sensor (NTC thermistor) inside the drum or heating circuit. Checking the sensor wiring and connections usually resolves it, though a replacement part may be needed.

Error code F03
Meaning Temperature sensor (NTC) fault or wiring failure
Severity Medium — the machine won’t heat water properly until fixed
Time to fix 20–45 minutes
Tools needed Multimeter, screwdriver (flat and Phillips)

What the F03 error means

F03 indicates the control board isn’t receiving a valid signal from the temperature sensor, which normally monitors water temperature during the wash cycle. This can happen because the sensor itself has failed, its wiring has come loose or corroded, or there’s a short circuit somewhere in the connection. Similar to the Indesit Washing F02 Error Code: Causes and Fixes, this is a component-level fault that often needs a physical inspection rather than a simple reset.

Common causes

  • Faulty or degraded NTC temperature sensor
  • Loose or disconnected wiring connector at the sensor
  • Corrosion or moisture damage on the sensor terminals
  • Damaged wiring harness between the sensor and control board
  • Control board fault misreading a working sensor
  • Sensor dislodged from its housing during a previous repair

How to fix the F03 error

  1. Power down and unplug the machine. Always disconnect power before opening any panels to avoid electric shock.
  2. Locate the temperature sensor. It’s usually attached to the heating element or the base of the drum housing, accessible from the back or bottom panel.
  3. Inspect the wiring connector. Check for looseness, corrosion, or discoloration and reseat the connector firmly.
  4. Test the sensor with a multimeter. Set to resistance mode and compare readings against the manufacturer’s spec sheet; a reading of zero or infinite resistance suggests a failed sensor.
  5. Replace the sensor if faulty. Order the correct Indesit replacement part and swap it in, making sure connectors click securely into place.
  6. Restore power and run a test cycle. Run a short wash without laundry to confirm the F03 code has cleared.

FAQ

Can I keep using the washing machine with an F03 error?
It’s not recommended. The machine may not heat water correctly, which can affect wash quality and, in some cases, trigger a full stop mid-cycle.

Is the temperature sensor expensive to replace?
No, the NTC sensor itself is a low-cost part, typically under £20/$25. Labour costs will vary if you hire a technician instead of doing it yourself.

Will unplugging the machine reset the F03 code?
Sometimes temporarily, but if the underlying wiring or sensor fault remains, the code will return once you start another cycle.