Er 8
Oven / Microwave
Electronic Control Board (PCB) & Bus CommunicationsMicrowave does not start, error message displayed. Disappears with Stop button.
Fuse F9 on microwave power module defective
Check/replace fuse F9 on microwave power module
Bosch Error Codes & Diagnostics
Access our premium database of error codes, common faults, and professional repair solutions for Bosch appliances.
Er8
Oven / Microwave
Drive Motor, Inverter & Tachometer SensorBosch Serie 6 / Serie 8 4D Hotair & EcoClean Direct Pyrolytic Oven: Combi-microwave generator circuit failure Er8; high-voltage generation absent or microwave inverter trips on safety shutoff.
On Bosch ovens: Defective high-voltage inverter PCB, shorted magnetron antenna dome, open...
DANGER HIGH VOLTAGE: Isolate power and discharge HV capacitor. Measure magnetron filament...
ER 9
Oven / Microwave
Heating Element, Thermostat & Safety FuseROM check error after reset, all heating elements switched off.
ROM check error after reset. Possible cause is a short power interruption or outage longer...
Perform another reset; the device should be ready for use again.
Er 11
Oven / Microwave
General System & Mechanical IntegrationBosch ER 11: Operational cycle fault detected during Oven / Microwave program execution.
Continuous pressing of a button for 10 seconds.
Stop continuously pressing the button; the error message will clear, and the button will...
Er13
Hob / Cooktop
General System & Mechanical IntegrationSporadic failure of the control unit with error message Er13
Software bug in older FD versions (up to FD 8011) or customer deactivating the buzzer (FD...
Electronics must be replaced (for older units). For specific FD versions, function can be...
Er 15
Oven / Microwave
Heating Element, Thermostat & Safety FuseOven is too hot, heating elements switched off, oven locked.
The actual temperature exceeds 380°C.
The oven will unlock when the temperature drops below 300°C. Start the customer service...
ErXY
Hob / Cooktop
General System & Mechanical IntegrationInternal error detected by electronics (display implied)
Electronics have detected an internal error.
1. Disconnect 230V mains power for 3 minutes. 2. Inspect wire harness and edge connectors...
F
Hob / Cooktop
General System & Mechanical IntegrationError display F in the display of a cooktop
Component fatigue, sensor feedback out of tolerance, wiring harness connector...
1. Disconnect 230V mains power for 3 minutes. 2. Inspect wire harness and edge connectors...
F0
Hob / Cooktop
Electronic Control Board (PCB) & Bus CommunicationsBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Internal hardware watchdog error F0; central microprocessor on power module triggers safety system shutdown.
On Bosch hobs: Clock oscillator drift, internal logic corruption on MCU, or unstable...
Perform hard power reset for 2 minutes. If F0 returns upon powering on, replace defective...
F1
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: LED display driver communication failure F1; touch user interface display controller communication dropout.
On Bosch hobs: Faulty 7-segment driver IC, damaged serial clock trace, or cracked...
Inspect UI board for cold solder joints around display ICs. Verify 3.3V DC supply to...
F2
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Cooking zone safety thermal shutdown F2; zone overheated and automatically turned off to protect glass surface.
On Bosch hobs: Pan boiled dry at high power, inadequate cabinet bottom ventilation gaps, or...
Remove pan and let cooktop cool down completely. Check cabinet airflow gaps (minimum 5mm...
F3
Hob / Cooktop
NTC Temperature Sensor & ThermistorBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Electronic heat sink over-temperature F3; power module aluminum heatsink thermistor exceeds 85°C limit.
On Bosch hobs: Blocked cooling air intake underneath cooktop, cooling fan failure, or...
Check under-counter ventilation space. Test cooling fan operation in service mode. Measure...
F4
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Safety time-limit auto shutdown F4; cooking zone has operated continuously without setting adjustments past limit.
On Bosch hobs: Normal safety feature triggered when zone left unattended on constant power...
This is not an electronic defect. Touch any key on the control panel to acknowledge the...
F5
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Control panel overheating warning F5; touch sensors detect excessive heat radiated from hot cookware placed over controls.
On Bosch hobs: Hot cooking pot, frying pan, or baking sheet positioned partially or...
Immediately remove hot cookware away from the touch control zone. The fault code clears...
F6
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Touch key continuous activation F6; liquid spillage or object resting on touch panel buttons for > 10 seconds.
On Bosch hobs: Overboiled soup or water covering capacitive buttons, damp dishcloth left on...
Remove any objects or cloth from the glass. Thoroughly wipe dry the touch control area with...
F7
Hob / Cooktop
General System & Mechanical IntegrationBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Zone switching relay failure F7; power relay contact stuck welded or relay driver transistor shorted.
On Bosch hobs: Heavy inductive load arcing welding 16A zone relay contacts, or failed...
De-energize hob. Check relay output contacts for continuity without power (must read open...
F8
Hob / Cooktop
Electronic Control Board (PCB) & Bus CommunicationsBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Resonant circuit frequency drift F8; induction coil resonant operating frequency outside calibrated window (20–45 kHz).
On Bosch hobs: Degraded high-voltage polypropylene resonant capacitor, loose coil screw...
Disconnect mains. Measure resonant film capacitors on power module with capacitance meter...
F9
Hob / Cooktop
Electronic Control Board (PCB) & Bus CommunicationsBosch Serie 6 / Serie 8 FlexInduction & PerfectFry Induction Cooktop: Auxiliary DC low-voltage rail out of regulation F9; 5V DC logic or 12V DC relay rail out of ±10% tolerance band.
On Bosch hobs: Failing flyback switch-mode power supply IC (e.g. LNK/Viper), swollen...
Inspect power board secondary side for bulged capacitors. Measure DC voltages at test...
F16
Washing Machine
Door Lock Mechanism & Safety InterlockBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Door interlock open fault F16; appliance cannot start wash program because door latch contacts remain unmade.
On Bosch washers: Laundry trapped between door glass and rubber bellows, worn mechanical...
Press door firmly until it clicks. Inspect door hook for mechanical damage. Measure...
F17
Washing Machine
Water Inlet Valve, Aquastop & FlowmeterBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Water inlet timeout alarm F17; appliance fails to reach required wash level within 5 minutes of filling.
On Bosch washers: Closed water supply tap, kinked fill hose, clogged mesh filter in...
Verify water tap pressure (min 10 L/min bucket test). Unscrew hose and clean inlet filter...
F18
Washing Machine
Drainage System & Drain PumpBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Draining timeout failure F18; washer fails to evacuate tub wastewater within programmed 6-minute window.
On Bosch washers: Coins, hairpins, or lint clogged in coin trap filter, kinked drain hose,...
Drain residual water via emergency drain tube. Unscrew pump filter cap and clear debris....
F19
Washing Machine
Heating Element, Thermostat & Safety FuseBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Heating timeout error F19; wash water temperature fails to increase by at least 4°C within 15 minutes of heating.
On Bosch washers: Open-circuit wash heating element (nominal ~24–28 Ω), open thermal fuse...
Disconnect power. Measure resistance across tubular heater terminals (nominal 24–28 Ω; open...
F20
Washing Machine
Heating Element, Thermostat & Safety FuseBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Unexpected heating fault F20; heater energized during cold rinse or water heats up without active command.
On Bosch washers: Welded heater relay contacts on power PCB, ground leakage shorting heater...
Check heater relay contacts for continuity when unpowered (must be normally open, infinite...
F21
Washing Machine
Drive Motor, Inverter & Tachometer SensorBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Motor drive / rotation failure F21; drum does not rotate, drive motor fails to turn or accelerate into spin.
On Bosch washers: Worn carbon brushes (< 12 mm on collector motors), open tachometer...
Check carbon brush length (replace if < 12 mm). Measure tachometer coil resistance (~15–20...
F22
Washing Machine
NTC Temperature Sensor & ThermistorBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Wash tub NTC temperature sensor fault F22; thermistor signal open circuit or shorted to ground, cycle runs cold.
On Bosch washers: Defective NTC thermistor inside heating element collar, corroded terminal...
Measure NTC resistance at 2-pin connector (nominal ~10 kΩ at 20°C, ~4.9 kΩ at 40°C, ~2.5 kΩ...
F23
Washing Machine
Drainage System & Drain PumpBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: AquaStop base float switch activated F23; water leak detected in bottom pan, safety drain pump runs continuously.
On Bosch washers: Water leak from cracked tub bellows gasket, loose hose clamp on drain...
Disconnect mains. Tilt washer backwards 45° to drain base tray and drop float switch....
F25
Washing Machine
Drainage System & Drain PumpBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Turbidity AquaSensor optical fault F25; infrared sensor cannot evaluate rinse water cloudiness or clarity.
On Bosch washers: Heavy soap scum / detergent residue on optical prism, disconnected 3-pin...
Inspect optical AquaSensor mounted on sump drain hose. Clean optical glass with isopropyl...
F26
Washing Machine
Water Level Pressure Switch & Air DomeBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Analog pressure sensor voltage out of range F26; sensor output signal voltage drops below 0.5V DC or exceeds 3.5V DC.
On Bosch washers: Blocked pressure chamber air trap, split or disconnected rubber hose, or...
Remove top lid. Inspect rubber hose between air trap and analog sensor. Clear pressure...
F27
Washing Machine
General System & Mechanical IntegrationBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Pressure sensor zero-point calibration drift F27; sensor reports residual water pressure with completely empty tub.
On Bosch washers: Trapped air pressure in sensor tube due to clogged sump trap, mechanical...
Disconnect pressure hose at sensor while tub is empty to equalize atmospheric pressure....
F28
Washing Machine
Water Inlet Valve, Aquastop & FlowmeterBosch Serie 4 / Serie 6 / Serie 8 / HomeProfessional EcoSilence Drive: Flow sensor impulse signal missing F28; water enters soap dispenser but reed switch flowmeter counts 0 pulses.
On Bosch washers: Jammed flowmeter turbine wheel (grit/scale deposit), broken reed switch...
Locate inline flowmeter behind inlet valve. Check turbine rotation under water flow. Verify...
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