Bosch Dishwasher Error Code F4

F4 on a Bosch dishwasher signals a water intake fault. The machine's control board monitors water flow by counting pulses from the flow sensor, and F4 triggers when fewer than 80 pulses are detected within the first 60 seconds, or when the total required pulse count is not reached within 255 seconds. The programme is interrupted to prevent the dishwasher from running without sufficient water.

A reset may clear the displayed code temporarily and allow the machine to attempt another cycle, but F4 will return if the underlying cause has not been resolved. Resetting without fixing the root issue, such as low water supply or a faulty inlet valve, will not prevent the fault from recurring. Use a reset only after addressing the cause as a way to confirm the repair was successful.

If the fix is as simple as opening a supply valve or cleaning the inlet hose filter screen, there is no parts cost at all. Replacing a water inlet valve typically costs between $25 and $80 for the part, while a new flow sensor usually falls in the $20 to $60 range. If a technician is required for diagnosis and installation, total repair costs including labor generally range from $100 to $250 depending on your location and the specific parts needed.

Start by confirming the water supply valve under the sink is fully open and the inlet hose is not kinked. Next, check and clean the inlet hose filter screen at the back of the machine. If the water supply is fine, the fault is likely the inlet valve or flow sensor, both of which may need to be tested for proper operation and replaced if defective. Also inspect the wiring and connectors linking those components to the control board.

The dishwasher interrupts the programme when F4 triggers, so it will not run a normal cycle in this state. Continuing to attempt cycles without resolving the fault is not recommended, as it could place additional stress on the pump and heating element if insufficient water is present. Diagnose and repair the water intake issue before resuming normal use.