OEM VERIFIED BENCH

OFFICIAL FAULT CODEF109

AEG // OFFICIAL DIAGNOSTIC BENCH

AEG F109

OvenNTC Temperature Sensor & Thermistor

Oven

Other Brands Sharing Code F109:MieleF109 ElectroluxF109 ZanussiF109 Arthur MartinF109 CastorF109 FaureF109 FrigidaireF109 KelvinatorF109 WestinghouseF109 ZoppasF109

Symptom / Description

FAULT

AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven: Cavity temperature sensor fault F109; electronic board detects open circuit or shorted PT500 / PT1000 temperature sensor.

TELEMETRY // LIVESIG: FAULT_DETECTED

Root Cause

ROOT CAUSE

On AEG (AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven) models: Open platinum thermal sensor element in oven back wall (nominal ~540 Ω for PT500 or ~1080 Ω for PT1000 at 20°C), broken wiring lead, or pinched heat-resistant cable.

CIRCUIT // SUBSYSTEMLOGIC: ROOT_ISOLATED

Repair Instructions

UNLOCKED

1Disconnect oven mains. Access rear panel cavity sensor harness. Measure resistance with multimeter (PT500 reads ~540 Ω at 20°C; PT1000 reads ~1080 Ω at 20°C). Rotate selector to 12 o'clock (OFF), press and hold Start/Pause and Exit simultaneously for 4 seconds until the diagnostic LED sequence resets error memory.

AI diagnostic workshop engine analyzing appliance circuit schematics and error telemetry in real time

AI WORKSHOP PROTOCOL ENGINE

Direct extraction from OEM factory manuals & wiring schematics

Field Actions

DISPATCH

Need Help? Call a Certified Technician Worldwide AEG Parts Finder

Electrical & Safety Protocol

Always disconnect appliance from 230V/400V mains before opening panels. Use CAT III multimeter for circuit testing.

CALIBRATED BENCH PROTOCOL // CAT III 600V

Workshop Verification & Safety Checklist

WORKSHOP VERIFICATION PROTOCOLNTC Temperature Sensor & ThermistorOven / Microwave

2. Multimeter & Electrical Bench Tests (Ω)

MODE: OHMMETER (Ω)AUTO-RANGE

Precision digital multimeter probes measuring electrical resistance in Ohms on an appliance control board

CALIBRATED METROLOGY RESISTANCE BENCH (CAT III)

Nominal Resistance (Ω)

4.8kΩ–12kΩ (at 20°C–25°C)NOMINAL

0 Ω (SHORT)CALIBRATED BAND∞ OL (OPEN)

▲ NOMINAL OPERATING WINDOW

Target Component:NTC Temperature Sensor Probe (Thermistor)

Test Pins & Connections

PROBE (+)

PROBE (-)

Across sensor pins 1-2 (unplugged harness)

Tolerance & Diagnostic CriteriaNegative temperature coefficient: resistance drops smoothly when warmed with fingers. OL = open circuit.

1. Pre-Intervention Electrical Safety Protocols

!Electrical Safety Protocol: Disconnect 230V electrical mains power before removing appliance side or rear panels.
!Ensure tub water or heating chamber has cooled below 30°C before unclipping thermistor probe.
!Use CAT III 600V/1000V insulated test probes when tng at PCB edge connectors.

3. Preliminary Mechanical & Visual Checks

Inspect sensor immersion sleeve for calcification, limescale scale, or thermal paste degradation.
Check wiring harness for pinch points, chafing against chassis metal, and terminal pin oxidation.
Verify probe is firmly seated in its rubber grommet or bracket inside the water/air circuit.

Perform these diagnostic steps before triggering AI Deep Search or replacing boards.Certified Workshop Routine

Frequently Asked Questions: AEG F109

FAQ TREE

What does error code F109 mean on a AEG appliance?

AEG error code F109 indicates: AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven: Cavity temperature sensor fault F109; electronic board detects open circuit or shorted PT500 / PT1000 temperature sensor..

What is the root cause of AEG error code F109?

The primary root cause for AEG code F109 is: On AEG (AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven) models: Open platinum thermal sensor element in oven back wall (nominal ~540 Ω for PT500 or ~1080 Ω for PT1000 at 20°C), broken wiring lead, or pinched heat-resistant cable..

How do I fix or resolve AEG error code F109?

To resolve error code F109: Disconnect oven mains. Access rear panel cavity sensor harness. Measure resistance with multimeter (PT500 reads ~540 Ω at 20°C; PT1000 reads ~1080 Ω at 20°C). Rotate selector to 12 o'clock (OFF), press and hold Start/Pause and Exit simultaneously for 4 seconds until the diagnostic LED sequence resets error memory.

Is it safe to clear AEG error code F109 by resetting power?

Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if AEG code F109 persists, the physical component causing On AEG (AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven) models: Open platinum thermal sensor element in oven back wall (nominal ~540 Ω for PT500 or ~1080 Ω for PT1000 at 20°C), broken wiring lead, or pinched heat-resistant cable. must be inspected or replaced.

How do I test electrical resistance for AEG code F109 using a multimeter?

Set a digital multimeter to ohms (Ω). Disconnect power and test NTC Temperature Sensor Probe (Thermistor) across Across sensor pins 1-2 (unplugged harness). Expected nominal reading is 4.8kΩ–12kΩ (at 20°C–25°C). Tolerance: Negative temperature coefficient: resistance drops smoothly when warmed with fingers. OL = open circuit..

What safety protocol must be followed before servicing AEG code F109?

Standard electrical safety protocol: 1. Disconnect 230V mains power before opening panels. 2. Verify zero voltage at test points. 3. Allow hot water or heating elements to cool below 30°C before handling.

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OEM VERIFIED BENCH

OFFICIAL FAULT CODEF109

AEG // OFFICIAL DIAGNOSTIC BENCH

AEG F109

OvenNTC Temperature Sensor & Thermistor

Oven

Other Brands Sharing Code F109:MieleF109 ElectroluxF109 ZanussiF109 Arthur MartinF109 CastorF109 FaureF109 FrigidaireF109 KelvinatorF109 WestinghouseF109 ZoppasF109

Symptom / Description

FAULT

AEG Competence / MaxiKlasse / SteamPro Pyrolytic Oven: Cavity temperature sensor fault F109; electronic board detects open circuit or shorted PT500 / PT1000 temperature sensor.

TELEMETRY // LIVESIG: FAULT_DETECTED

Root Cause

ROOT CAUSE

CIRCUIT // SUBSYSTEMLOGIC: ROOT_ISOLATED

Repair Instructions

UNLOCKED

AI WORKSHOP PROTOCOL ENGINE

Direct extraction from OEM factory manuals & wiring schematics

Field Actions

DISPATCH

Need Help? Call a Certified Technician Worldwide AEG Parts Finder

Electrical & Safety Protocol

Always disconnect appliance from 230V/400V mains before opening panels. Use CAT III multimeter for circuit testing.

CALIBRATED BENCH PROTOCOL // CAT III 600V

Workshop Verification & Safety Checklist

WORKSHOP VERIFICATION PROTOCOLNTC Temperature Sensor & ThermistorOven / Microwave

2. Multimeter & Electrical Bench Tests (Ω)

MODE: OHMMETER (Ω)AUTO-RANGE

CALIBRATED METROLOGY RESISTANCE BENCH (CAT III)

Nominal Resistance (Ω)

4.8kΩ–12kΩ (at 20°C–25°C)NOMINAL

0 Ω (SHORT)CALIBRATED BAND∞ OL (OPEN)

▲ NOMINAL OPERATING WINDOW

Target Component:NTC Temperature Sensor Probe (Thermistor)

Test Pins & Connections

PROBE (+)

PROBE (-)

Across sensor pins 1-2 (unplugged harness)

Tolerance & Diagnostic CriteriaNegative temperature coefficient: resistance drops smoothly when warmed with fingers. OL = open circuit.

1. Pre-Intervention Electrical Safety Protocols

!Electrical Safety Protocol: Disconnect 230V electrical mains power before removing appliance side or rear panels.
!Ensure tub water or heating chamber has cooled below 30°C before unclipping thermistor probe.
!Use CAT III 600V/1000V insulated test probes when tng at PCB edge connectors.

3. Preliminary Mechanical & Visual Checks

Inspect sensor immersion sleeve for calcification, limescale scale, or thermal paste degradation.
Check wiring harness for pinch points, chafing against chassis metal, and terminal pin oxidation.
Verify probe is firmly seated in its rubber grommet or bracket inside the water/air circuit.

Perform these diagnostic steps before triggering AI Deep Search or replacing boards.Certified Workshop Routine

Frequently Asked Questions: AEG F109

FAQ TREE

What does error code F109 mean on a AEG appliance?

What is the root cause of AEG error code F109?

How do I fix or resolve AEG error code F109?

Is it safe to clear AEG error code F109 by resetting power?

How do I test electrical resistance for AEG code F109 using a multimeter?

What safety protocol must be followed before servicing AEG code F109?

Community Verification

COMMUNITY

Did this solution resolve the issue?

AEG F109

Symptom / Description

Root Cause

Repair Instructions

Field Actions

Workshop Verification & Safety Checklist

Frequently Asked Questions: AEG F109

Community Verification

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AEG F109

Symptom / Description

Root Cause

Repair Instructions

Field Actions

Workshop Verification & Safety Checklist

Frequently Asked Questions: AEG F109

Community Verification

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