Miele Dishwasher Error Code F78

F78 on a Miele dishwasher indicates a circulation pump fault. The control board has detected either a failed or non-functioning circulation pump, or an interrupted electrical connection between the control electronics and the door contact switch. The dishwasher will not complete a wash cycle until the fault is resolved.

No, you should not continue running the dishwasher while F78 is active. The circulation pump is not operating correctly, meaning water is not being properly circulated during the wash cycle. Running the appliance in this state can stress other components and will not produce clean dishes.

Repair costs for an F78 fault vary depending on the root cause. A wiring repair or connector fix is typically on the lower end of the cost range. A circulation pump replacement on a Miele dishwasher generally falls in the range of $150 to $400 including parts and labor, while an SLT control board replacement can cost $200 to $500 or more depending on the specific model and service rates in your area.

Some causes of F78 can be addressed by a knowledgeable DIYer. Checking wiring harness connectors for looseness or corrosion and inspecting the door contact switch connections are reasonable first steps. However, measuring voltage at the SLT board terminals and replacing the circulation pump or control board typically requires electrical diagnostic experience and familiarity with dishwasher disassembly.

A reset may temporarily clear the F78 code, but it will return if the underlying fault is not repaired. The error is triggered by a real electrical or mechanical condition, so resetting without fixing the wiring, door contact switch, or circulation pump will not resolve the problem.