The “Indesit Dishwasher Virtual Sensor Error” is a technical fault that occurs in modern Indesit models (specifically those with BLAC motors) where the appliance loses its ability to detect water levels or motor status. Unlike older machines that rely on a physical pressure switch, these dishwashers use a Virtual Sensor system that monitors the electrical resistance and power consumption of the Wash pump and Drain pump to “sense” if the water is full, empty, or if the filter is clogged.
The error is most explicitly displayed as F15 (“Virtual Sensor Error”), but because the system relies entirely on the pumps, it is frequently accompanied by or misdiagnosed as F11 (Wash Pump Failure) or F05 (Drain Failure).
Below is the comprehensive troubleshooting guide for resolving this issue.
Indesit Dishwasher Virtual Sensor Error: Diagnosis and Repair
The Indesit Dishwasher Virtual Sensor Error is a complex fault indicating a breakdown in the communication between the main control board and the appliance’s motor components. Because the “sensor” is software-based rather than a physical part you can touch, fixing this error requires diagnosing the physical components that feed data to that software: primarily the circulation pump and drain system.
Understanding the Virtual Sensor System
In newer Indesit models, the manufacturer removed the traditional mechanical pressure switch (which used air pressure to detect water levels). Instead, the PCB (Printed Circuit Board) monitors the electrical load on the motors:
- Low Resistance: The pump is spinning freely (no water = empty).
- High/Correct Resistance: The pump is pushing water (resistance = full).
- Fluctuating Resistance: There is air in the system, foam, or a blockage (virtual sensor fault).
When the data from the Wash pump or Circulation pump becomes erratic, the Control Board triggers the Virtual Sensor Error (often F15), stopping the cycle to prevent damage.
Common Error Codes Linked to Virtual Sensors
While F15 is the direct code for the virtual sensor, the following codes are part of the same ecosystem and often appear during troubleshooting:
- F11 Error Code: This indicates a specific failure of the Wash pump. Since the wash pump is the primary virtual sensor, a failing pump motor is the #1 cause of the virtual sensor error.
- F05 Error Code: This indicates a Drain hose blockage or pump timeout. If the drain pump cannot empty the water, the virtual sensor logic cannot reset to “Empty,” causing a conflict.
Troubleshooting Steps
1. Inspect the Filter and Sump
The virtual sensor is extremely sensitive to water turbulence. A clogged Filter can starve the pump of water, causing the motor’s resistance to drop and tricking the sensor into thinking the machine is empty or surging.
- Remove the fine mesh filter and the central cylindrical filter.
- Clean them thoroughly under hot water.
- Check the sump (the hole at the bottom) for solid debris like broken glass or bone fragments that could jam the pump impeller.
2. Check the Wash Pump (Circulation Pump)
The Wash pump is the heart of the virtual sensor system. If this pump has worn bearings or a weak capacitor, it will send incorrect data to the Control board.
- Disconnect power to the dishwasher.
- Access the pump from the bottom of the unit.
- Visual Check: Look for signs of water leaking onto the pump coils.
- Mechanical Check: Ensure the impeller spins freely. If it feels “gritty” or stuck, the pump is mechanically seized and must be replaced.
- Electrical Check: If you have a multimeter, check the resistance across the pump terminals. An open circuit (infinity ohms) confirms the motor is dead.
3. Clear the Drain System (F05 / Drain Faults)
If the machine holds water, the virtual sensor cannot calibrate.
- Check the Drain hose for kinks or blockages, especially where it connects to the sink spigot.
- Inspect the drain pump impeller for obstructions.
- Ensure the Flow meter (if present on your specific model) is not jammed, as this measures water intake volume and works in tandem with the virtual sensor logic.
4. Resetting the Control Board
Sometimes the “Virtual Sensor Error” is a software glitch caused by a power surge or a momentary pump stall.
- Turn off the dishwasher and unplug it from the mains.
- Wait for 15–20 minutes to allow the capacitors on the PCB to discharge.
- Plug it back in and run a short cycle.
- Note: If the error returns immediately, it is a hard component failure (likely the wash pump), not a glitch.
When to Call for Appliance Repair
If you have cleaned the filters, verified the drain path is clear, and the Indesit Dishwasher Virtual Sensor Error persists, the fault likely lies within the Wash pump electronics or the Control board itself. Replacing the wash pump is a moderate-level repair. If you are uncomfortable working with high-voltage wiring or hose clamps, it is recommended to contact a professional for Appliance repair.
Summary of Parts to Check:
- Wash Pump (Most Likely)
- Drain Pump
- Main Filter & Sump
- Main Control Board (PCB)
By methodically checking these components, you can isolate whether the “virtual” error is caused by a physical blockage or a failing motor.
Frequently Asked Questions
What exactly is a Virtual Sensor in an Indesit dishwasher?
Unlike older dishwashers that use a physical pressure switch to detect water, the virtual sensor is a software-based system. It determines water levels and appliance status by monitoring the electrical resistance and power consumption of the wash and drain pumps. If the pump is pushing water, the resistance is high; if it is spinning in air, the resistance is low.
What is the most common cause of the F15 error code?
The most common cause is a failing or blocked wash pump (circulation pump). Since the virtual sensor relies on the wash pump to provide data to the control board, any mechanical wear, seized bearings, or electrical failure in the pump will trigger the F15 “Virtual Sensor Error.”
Can a dirty filter trigger a sensor error?
Yes. If the fine mesh filter or the sump is clogged with debris, it can cause water turbulence or prevent water from reaching the pump. This causes the motor’s resistance to fluctuate wildly, which the control board interprets as a virtual sensor fault. Cleaning your filters is the first step in troubleshooting this error.
How do I reset my Indesit dishwasher to clear this error?
To perform a software reset, turn off the dishwasher and unplug it from the power source for 15 to 20 minutes. This allows the capacitors on the main control board (PCB) to discharge completely. If the error was caused by a temporary power surge or a minor pump stall, the machine may function normally after being plugged back in.
Are error codes F11 and F05 related to the virtual sensor?
Yes, they are closely linked. F11 indicates a wash pump failure, and F05 indicates a drain failure. Because the virtual sensor system uses these specific pumps to “sense” the water level, a problem with either pump often causes the virtual sensor logic to fail, leading to an F15 error.