Miele Dishwasher Error Code F70: Waterproof System Activated (Meaning, Causes, What to Do)
What the code means
Miele's support pages (USA, Canada, UK and Australia) all describe F70 the same way: "The water protection system has reacted. The current program is canceled and the drain pump switches on." Miele's operating instructions explain what that system is: every Miele dishwasher has a safety valve on the incoming water line and a sealed underside with a water sensor, and if a fault occurs the water intake is stopped and the drain pump is activated. Miele's G 600/G 800 technical information shows the hardware behind it: the inlet hose and valves sit inside a protective outer sleeve, so a leaking valve or hose sends water along that sleeve into the drip tray in the bottom of the machine, where a float switch (B8/3) trips and starts the drain pump. Newer manuals add that the Waterproof system works even when the dishwasher is switched off, as long as it stays plugged in. Older models without a code display signal the same reaction with the flashing Inlet/drain light instead of F70. Don't confuse F70 with F11, a drain fault, or F78, a blocked circulation pump.
Likely causes
- A leak inside the machine that drips into the sealed base pan, such as a loose or split internal hose or a leaking seal, which lifts the float switch.
- A leaking water inlet valve or inlet hose, which Miele's design routes through the hose's outer sleeve into the drip tray.
- Water left in the base pan from an earlier leak, which keeps the float switch up.
- A float switch or sensor that has failed, though Miele treats any F70 as a fault for its service team to check.
Safe DIY checks
Turn off the water and unplug the dishwasher before you touch anything; water and line voltage meet in the base of the machine. The inlet connection housing contains an electrical valve, so never cut the hose or submerge that housing. Moving and opening the machine to reach the base pan is a job for Miele Service or a qualified appliance technician.
- Close the water faucet or shutoff valve that feeds the dishwasher.
- Turn the dishwasher off and unplug it, or switch off its breaker if the plug isn't reachable. The drain pump keeps running until power is removed, which is normal.
- Unload the dishes, wipe up any water on the floor and check the outside of the water connection at the faucet for drips. If the screw connection drips, tighten it, as Miele's instructions describe.
- Look along the inlet hose for kinks, crushing or splits. Don't cut it or put the connection housing in water: it contains an electrical valve.
- Leave the water off and contact Miele Service. Miele lists no user reset for F70, so don't keep restarting the machine to see if it clears.
🛠 When to call a pro
- Pull the dishwasher out, drain and dry the base pan, and find the leak source before returning it to service.
- Inspect the internal hoses, sump and pump seals, the inlet valve and the Waterproof hose's outer sleeve, and replace whatever is leaking.
- Check the base-pan float switch and its wiring, and confirm it drops back once the pan is dry.
- Replace a damaged Waterproof inlet hose with the correct Miele part, since the hose carries electrical components.
Parts that commonly fix it
Always match the part number to your exact model.
Water leak detector
A cheap alarm on the floor under the sink or next to the dishwasher warns you of the next leak early.
Search eBay →Dishwasher supply line
Only for the household line up to the shutoff valve; the Miele Waterproof hose itself must be a Miele part.
Search eBay →Multimeter
For a technician checking the float switch and wiring with the machine unplugged.
Search eBay →Sources
- Miele USA support, Fault F70 (Waterproof system): the water protection system has reacted, program canceled, drain pump on; close faucet, turn off, unplug, contact Miele Service
- Miele Great Britain support, Fault F70 (Waterproof system)
- Miele USA support, Inlet/drain indicator light flashing (Waterproof system reaction on lighted models, inlet filter cleaning, electrical valve in the connection housing)
- Miele G 1182/G 2182 Operating Instructions: Waterproof system (safety valve on the water line, sealed underside with water sensor) (Miele USA)
- Miele dishwasher Operating Instructions: Waterproof system works when switched off but plugged in, conditions for protection (Miele media)
- Miele G 600/G 800 Technical Information: WaterProof System outer sleeve and drip-tray float switch B8/3 (via ManualsDump)
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.