Miele Dishwasher F78: Circulation Pump Electronics

F78 flags the circulation pump’s electronic drive. Modern Miele circulation pumps are BLDC units with their own control electronics; F78 means the main control and the pump’s drive stopped agreeing — no or implausible feedback, failed commutation, or a supply problem at the pump module.

What you’ll notice

Cycle starts, fills, then goes quiet where wash action should be — or aborts minutes in with F78. Sometimes it’s intermittent for weeks (cycle completes on the second try) before failing hard. Intermittent-then-hard is the classic electronics degradation curve.

Anything to try yourself?

One clean attempt: power the machine down at the breaker for ten minutes, restore, run a short program. A single F78 after a power event (outage, surge, generator switchover) can be a latch-up that clears. If F78 repeats, further resets accomplish nothing — the pump module or its supply needs measurement.

Worth knowing for this area: homes with older panels and aggressive summer AC load see more voltage sag; we’ve traced repeat F78s in Concord and Pleasant Hill to supply dips rather than a bad pump. Part of our diagnostic is checking what the machine actually receives.

The repair

We test drive-stage supply, feedback signals and winding condition per Miele service data. Outcome is usually a circulation pump (with integrated electronics) replacement — an OEM assembly we stock — or, less often, power-board work. Either way it’s a same-visit repair when booked with the code mentioned.

FAQ

Is F78 the same as “the pump is clogged”?

No — blockage shows differently (F14 territory or noise). F78 is electronic. A blocked pump can lead to drive stress though, so we check both.

The dishwasher is only 4 years old. Should this fail?

It shouldn’t, and if your unit is within Miele’s warranty terms we handle the claim paperwork as an authorized servicer — that’s the point of using one.

Will a surge protector help after the repair?

On homes with known power events, yes — cheap insurance for every appliance with inverter electronics.