Miele Dishwasher F70 / Waterproof System Activated

F70 means water where it never belongs: in the base pan under the tub. A float switch sits down there; when it lifts, the machine locks intake, runs the drain pump — sometimes continuously — and shows F70 or “Waterproof system activated.” This is the fault where doing the right thing in the first ten minutes matters.

Do this now

1. Close the water supply valve under the sink.
2. Let the drain pump run if it’s running — it’s emptying the pan.
3. Don’t tilt the machine “to pour it out.” You’ll push water into electronics that stayed dry.
4. Put a towel under the door and book service. This one isn’t a reset-and-hope code.

Where the water actually comes from

Field ranking from our Pleasant Hill/Concord calls: sump and pump housing seals, a split or loose internal hose, a cracked spray-arm feed, door-gasket leaks running down inside the cabinet, and — less often — condensation accumulation from years of marginal drainage (see F11). On older machines, a corroded heater flange makes the list.

The visit involves pulling the machine, drying and inspecting the pan with the source identified under pressure, replacing the failed seal/hose/component, and verifying the float and its switch. Skipping the “identify under pressure” step is why hand-dried F70s come back in two weeks.

FAQ

The pump won’t stop running and it’s loud. Unplug it?

If the pan is emptying, let it finish, then power down and close water. Continuous pump run is the designed emergency behavior.

Can I just dry the pan and keep using the machine?

The float will drop and it’ll run — until the same leak refills the pan, possibly onto your floor. F70 without a found-and-fixed source is a countdown.

Does homeowners insurance care about this?

An activated Waterproof system means the machine contained the leak — that’s the story you want. We document the failed part for your records on request.