Bosch Dishwasher Error Code E04 — What It Means & How to Fix It

What Does This Error Mean?

Bosch dishwasher error E04 means the flow sensor has detected an unexpected water flow reading. The flow sensor measures how much water enters the machine during the fill cycle. If the reading is wrong or the sensor fails completely, the dishwasher cannot manage water correctly and stops the cycle.

Affected Models

Bosch Series 2
Bosch Series 4
Bosch Series 6
Bosch Series 8
Bosch Silence Plus

Common Causes

The flow sensor is blocked with limescale or debris and cannot measure water flow accurately
The flow sensor has failed electrically and is not sending a signal to the control board
The water inlet valve is partially blocked, causing abnormal flow readings
Air trapped in the water supply line is interfering with the flow sensor's measurement
A wiring fault between the flow sensor and the control board is disrupting the signal

How to Fix It

Reset the dishwasher by turning it off at the wall and leaving it unplugged for 5 minutes. Plug back in and run a short test cycle to see if the error clears.

Temporary sensor glitches caused by air in the line often clear with a simple reset.
Check the inlet filter mesh. Turn off the water supply, disconnect the inlet hose from the back of the dishwasher, and clean the small filter screen at the connection point.

Limescale on the filter can reduce water flow and confuse the flow sensor into reading incorrectly.
Run your kitchen tap briefly before starting the dishwasher. This purges any air from the supply line that could cause a false E04 reading during the fill cycle.

Air in the pipes is more common after the water supply has been shut off for plumbing work.
Check that the water supply tap is fully open. A partially open tap can create an inconsistent flow rate that confuses the sensor.

Turn the tap fully counterclockwise to make sure it is all the way open.
If the error continues after cleaning and resetting, book an appliance technician to test the flow sensor with a multimeter and replace it if faulty.

Flow sensor replacement is a moderate repair — typically $80 to $150 including parts and labor.

When to Call a Professional

If the E04 error persists after cleaning the inlet filter and resetting the machine, the flow sensor likely needs replacing. The flow sensor is located in the water inlet area and requires partial disassembly of the dishwasher to access. An appliance technician can replace it in about an hour.

Frequently Asked Questions

What is a flow sensor in a dishwasher?

A flow sensor (also called a flow meter or turbine sensor) sits in the water inlet path. It spins as water flows past it and sends pulses to the control board to measure the volume of water entering the machine. The dishwasher uses this data to control the fill level accurately.

Is E04 the same as E14?

They are related but slightly different. E04 indicates an abnormal flow reading — the sensor is present but the reading is outside the expected range. E14 means the flow sensor is not sending any signal at all. Both usually require flow sensor replacement.

Can limescale actually cause this error?

Yes — in hard water areas, limescale can coat the turbine inside the flow sensor and prevent it from spinning freely. This causes incorrect flow readings that trigger E04. Regular use of dishwasher salt and descaler helps prevent this.