This guide explains all KitchenAid Microwave error codes (CH series) with simple troubleshooting steps to help you identify and fix common issues safely before calling a technician.
F1
Touch Panel Shorted
- Disconnect power for 5–10 minutes.
- Clean control panel surface from moisture or grease.
- Inspect ribbon cable connection.
- Replace touch panel if short persists.
F2
Overheating Detected
- Allow microwave to cool completely.
- Check ventilation openings for blockage.
- Inspect thermal sensor or thermostat.
- Replace thermal cutoff if needed.
F3
Humidity Sensor Failure
- Inspect sensor wiring connections.
- Check for moisture or corrosion damage.
- Test sensor resistance with multimeter.
- Replace humidity sensor if faulty.
F4
Door Switch Fault
- Check door alignment and latch.
- Inspect interlock switches for damage.
- Test continuity of door switch system.
- Replace switch assembly if needed.
F5
Relay Control Failure
- Reset microwave power supply.
- Inspect control board relay circuit.
- Check wiring to high-voltage components.
- Replace control board if relay is faulty.
F6
High Voltage Transformer Fault
- Check transformer for overheating or damage.
- Inspect wiring connections.
- Test high-voltage circuit components.
- Replace transformer if faulty.
F7
Magnetron Failure
- Check magnetron for burning smell or damage.
- Inspect high-voltage capacitor.
- Test diode and transformer output.
- Replace magnetron if defective.
F8
Cooling Fan Failure
- Inspect fan motor and blades.
- Check for obstruction or dust buildup.
- Test fan power supply.
- Replace fan motor if needed.
F9
Inverter Board Error
- Reset microwave power cycle.
- Inspect inverter board connections.
- Check for burnt components.
- Replace inverter board if faulty.
F10
Turntable Motor Failure
- Check turntable motor for obstruction.
- Inspect gear alignment.
- Test motor resistance.
- Replace motor if not rotating.
F11
Power Supply Instability
- Check outlet voltage stability.
- Inspect power cord for damage.
- Reset circuit breaker.
- Contact electrician if issue persists.
F21 / E21
Motor Failure / Drive Jam
- Check turntable motor for blockage.
- Inspect drive mechanism.
- Remove internal obstructions.
- Replace motor if needed.
F12
Keypad Communication Failure
- Check ribbon cable between keypad and control board.
- Inspect for loose or corroded connectors.
- Reset power to the unit.
- Replace keypad assembly if issue persists.
F13
Control Board Memory Error
- Perform full power reset for 10 minutes.
- Check for voltage fluctuations.
- Inspect main PCB for damage.
- Replace control board if memory fails.
F14
Excessive Internal Humidity
- Allow microwave to dry completely.
- Check ventilation system.
- Inspect steam vent and seals.
- Replace humidity sensor if needed.
F15
Thermal Fuse Open Circuit
- Check thermal fuse continuity.
- Inspect overheating history.
- Check airflow restrictions.
- Replace thermal fuse if blown.
F16
Door Latch Misalignment
- Inspect door hinges and alignment.
- Check latch hook condition.
- Ensure door closes firmly.
- Replace latch assembly if damaged.
F17
Cooking Sensor Calibration Error
- Reset microwave calibration mode.
- Clean sensor area inside cavity.
- Test sensor response.
- Replace sensor if inaccurate.
F18
High Voltage Diode Failure
- Inspect high-voltage diode for burn marks.
- Test diode with multimeter.
- Check capacitor and transformer condition.
- Replace diode if faulty.
F19
Low Power Output Issue
- Check magnetron performance.
- Inspect inverter or transformer system.
- Test power supply stability.
- Replace magnetron if weak output detected.
F20
Stuck Relay on Control Board
- Reset power to release relay lock.
- Inspect relay contacts for welding.
- Check control board for overheating.
- Replace PCB if relay is stuck.
F22 / E22
Cooling System Airflow Restriction
- Clean air vents and fan housing.
- Check cooling fan operation.
- Remove dust buildup inside unit.
- Replace fan motor if airflow is weak.
F23 / E23
Voltage Surge Protection Triggered
- Unplug microwave and wait 10 minutes.
- Check household power stability.
- Inspect surge protection components.
- Replace control board if damaged.
F24 / E24
Door Interlock System Failure
- Inspect all door interlock switches.
- Check wiring harness to door assembly.
- Test continuity of safety switches.
- Replace interlock system if faulty.