Bosch Dishwasher Error Code F3

F3 on a Bosch dishwasher indicates a thermistor fault. The control unit has detected either an interruption in the thermistor circuit or a temperature reading above 80 degrees Celsius. When F3 activates during the heating stage, the dishwasher exits that stage and continues the cycle without heating the water.

A reset may temporarily clear the F3 code, but if the underlying fault is still present the error will return, typically during the next heating cycle. Resetting without repairing the root cause will not fix the problem. A persistent or returning F3 code requires proper diagnosis of the thermistor, wiring, and control unit.

Repair costs depend on the component that has failed. A replacement thermistor is typically an inexpensive part, with DIY repair costs ranging from around 10 to 40 dollars for the part alone. If professional labor is required, expect to pay between 80 and 200 dollars depending on your location and the technician. A control unit replacement is significantly more expensive, often ranging from 150 to 400 dollars or more for parts and labor.

Some causes of F3 are DIY-friendly, such as reseating a loose thermistor connector or inspecting visible wiring for damage. Testing the thermistor with a multimeter requires basic electrical knowledge. Replacing the thermistor is a straightforward repair for someone comfortable working inside a dishwasher, but diagnosing or replacing the control unit is best left to a qualified technician.

Running the dishwasher with an active F3 error is generally not a safety hazard, since the machine exits the heating stage rather than continuing to heat uncontrolled. However, your dishes will not be washed at the correct temperature, which reduces cleaning effectiveness and may not sanitize properly. It is advisable to diagnose and repair the fault before continued regular use.