Ad Space — Top Banner

F1

Sharp Microwave

Severity: Moderate

Source: OnlyErrorCodes.com — Every error code. One place.

Sharp Microwave F1 Error — Sensor Fault

What Does This Error Mean?

F1 on a Sharp microwave means the temperature sensor (thermistor) is faulty, disconnected, or reading out of range. The microwave will not start until F1 clears. A power cycle may resolve a temporary fault — persistent F1 requires sensor replacement.

Affected Models

  • Sharp R-651ZS
  • Sharp R-1214
  • Sharp Carousel R-21LCFS
  • Sharp SMC2242DS
  • Sharp R-820JS

Common Causes

  • Failed thermistor (NTC temperature sensor) inside the cavity
  • Sensor wiring loose at the connector after vibration
  • Damage from a previous overheating event (e.g., metal in the cavity)
  • Control board fault affecting sensor input (less common)

How to Fix It

  1. Unplug the microwave for 5 minutes.

    Disconnecting power resets the control board logic. After 5 minutes, plug back in. If F1 has cleared, test with a 30-second cook on a cup of water.

  2. Allow to cool fully if recently used heavily.

    If F1 followed a long cooking session, the sensor may simply be too hot to read accurately. Leave the microwave open and unplugged for 30 minutes to fully cool, then retry.

  3. Inspect the cavity for damage.

    Look inside the microwave for any signs of arcing burns or damage from metal items. A previous metallic event can damage the thermistor and cause F1. Damaged cavity walls require repair before reuse.

  4. Book service if F1 persists.

    Persistent F1 after a cool-down and power cycle means the thermistor or its wiring needs replacement. Sharp service or an authorised technician can replace the sensor — typical cost is USD 100–180 fitted.

Frequently Asked Questions

Will my Sharp microwave operate with F1 showing?

No — F1 prevents the microwave from starting any cooking cycle. Sharp's safety logic disables operation when the temperature sensor cannot be trusted, to prevent overheating without protection.

How long should a Sharp thermistor last?

A Sharp microwave thermistor typically lasts 8–15 years in normal use. Earlier failure usually follows a metal-in-cavity arcing event or repeated severe burning, both of which damage the sensor.