Miele Dishwasher Error Code F79

• Dishwasher displays F79 error code on the control panel
• Dishes and glassware come out cold or lukewarm instead of hot
• Wash cycle completes but with poor cleaning results
• Drying cycle may not function properly
• Dishwasher may stop mid-cycle or refuse to start
• No audible heating element activation during wash cycles

• Faulty heating element unable to reach required 120V operational temperature
• Defective temperature sensor providing incorrect water temperature readings
• Broken or loose heating element wire connection
• Thermistor (temperature probe) failure
• Water inlet temperature too low for the sensor to calibrate properly
• Mineral buildup on heating element reducing efficiency
• Control board malfunction preventing proper heating circuit activation
• Blown thermal fuse in the heating circuit
• Failed heating relay or contactor on the main control board

• Verify your home circuit breaker for the dishwasher is switched ON and has not tripped; if tripped, switch it OFF then back ON
• Check that your dishwasher's inlet water valve is fully open (turn counterclockwise if needed) - located at the water supply connection under the sink
• Remove and clean the dishwasher's filter screen thoroughly under running water to ensure no debris is blocking water flow
• Inspect both upper and lower spray arms for visible clogs or debris; rotate arms by hand to confirm they spin freely
• Ensure the dishwasher door is fully closed and latches completely with an audible click
• Perform a hard reset by switching OFF the circuit breaker for 60 seconds, then switch it back ON to clear any temporary control board errors
• Run a rinse cycle only (without dishes) to see if the dishwasher shows any improvement or changes in behavior
• Check that hot water is available at other fixtures in your home to confirm your water heater is functioning properly