Smeg dishwasher with error code E9

As an expert technician, I have diagnosed the Smeg dishwasher with error code E9. This specific fault code indicates a Water Intake System Failure. It occurs when the appliance detects that water is not entering the tub correctly, the flow rate is insufficient, or the Main Control Board is not receiving pulses from the Flow Meter (impeller) within the allotted time frame.

Smeg dishwasher with error code E9: Diagnostic Report & Troubleshooting Steps

1. Check Water Supply: Ensure the external water tap is fully open and that there are no kinks in the Inlet Hose. Verify that your home’s water pressure is adequate.
2. Inspect the Inlet Filter: Unscrew the Inlet Hose from the back of the dishwasher. Use needle-nose pliers to remove the small plastic mesh filter inside the Water Inlet Valve port. Clean any sediment or limescale and reinstall.
3. Test the Water Inlet Valve: Access the base of the dishwasher. Disconnect the wires from the Water Inlet Valve and use a multimeter to check for continuity and resistance.
4. Inspect the Flow Meter: The Flow Meter is typically located on the side of the Water Softener or Heat Exchanger assembly. Ensure the internal impeller is spinning freely and that the electrical plug is secure and free of corrosion.
5. Check the Pressure Switch: Ensure the thin rubber tube leading to the Pressure Switch is not blocked by debris or “gunk,” which can cause false air pressure readings.
6. Verify Wiring Harness: Inspect the wiring between the Water Inlet Valve, Flow Meter, and the Main Control Board for any signs of breaks, burns, or loose connections.

Expected Ohmic/Resistance Values

• Water Inlet Valve: 3500 Ω – 4500 Ω (3.5k – 4.5k Ω). A reading of “OL” or 0 Ω indicates a failed solenoid coil.
• Flow Meter: This component typically uses a reed switch. While it cannot be easily tested for a specific resistance range while static, you should see the resistance toggle between 0 Ω and infinite (OL) when a magnet is passed near it or when water spins the internal impeller.
• Pressure Switch: Should show 0 Ω (continuity) when the diaphragm is engaged and infinite (OL) when at rest.

Estimated Repair Cost

• Water Inlet Valve: $30 – $65 USD
• Flow Meter / Impeller Sensor: $25 – $55 USD
• Pressure Switch: $35 – $70 USD
• Main Control Board (if the logic circuit has failed): $120 – $220 USD

Warning: Always disconnect the dishwasher from the electrical power supply and turn off the water source before attempting any internal inspections or repairs. Working on an appliance while it is plugged in poses a severe risk of electric shock. If you are testing live voltage, use extreme caution and insulated tools.

Repair Difficulty: Intermediate DIY. Most owners can replace the Water Inlet Valve or clean filters with basic tools. However, accessing the Flow Meter or Main Control Board may require significant disassembly of the side panels or base, which may require a professional if you are not comfortable with complex appliance teardowns.