What causes Miele Dishwasher F12?

The faucet or shutoff valve feeding the dishwasher is closed or only partly open (Miele's first cause). A dirty or blocked plastic filter in the screw connection of the water intake valve at the faucet. A kinked or looped water inlet hose. Household flow pressure below 7.25 psi (0.5 bar); the technical manual says supply pressure below 14.5 psi should be checked by a specialist. A defective water inlet valve (the WaterProof System valve) that isn't opening. The flow meter not sending pulses (reed switch, its circuit board or plug), or an open circuit in its wiring. Less often, a fault in the water diverter or the electronic board.

How do I fix Miele Dishwasher F12?

Make sure the faucet or shutoff valve feeding the dishwasher is fully open. Straighten the water inlet hose and remove any kinks or loops. Keep an eye on those spots afterward, since Miele says the plastic can weaken and tear; a damaged hose has to be replaced. Clean the inlet filter. Switch the dishwasher off, unplug it and close the faucet. Unscrew the water intake valve from the faucet, remove the seal, then pull the plastic filter out by its bar with combination or needle-nose pliers. Rinse the plastic filter under running water. Don't dip the plastic housing at the water connection in water; Miele warns it contains an electrical valve. Put the filter and seal back so they're seated correctly (the filter must go back in), screw the connection securely onto the faucet, and open the faucet slowly. Tighten the connection if it drips. If other taps in the house are weak too, have a plumber or the building manager check the supply. Miele says flow pressure must be at least 7.25 psi (0.5 bar). Switch the dishwasher back on and start a program. If F12 returns with the water fully on, note the model and serial number from the rating plate on the edge of the door and contact Miele Service (US 888-996-4353).

When should I call a pro for Miele Dishwasher F12?

F12 comes back with the faucet open, a clean filter and a straight hose: a technician checks the inlet valve. Miele's technical manual has them start a program and feel the valve housing during the fill step; if it vibrates, the valve is getting power and gets replaced, and if not, they trace power from the valve connector back to the electronic board. The valve opens and water flows but F12 persists: the technician checks the flow meter's reed switch, its plug and its wiring. The manual's test is to pass a magnet over the reed switch; if that produces a pulse, the water diverter is replaced, and if not, the reed switch is. The flow meter reads pulses and F12 still shows: the manual says to replace the electronic board. The dishwasher is under warranty or extended cover: use Miele Service first.

Code: F12🧺 Miele Dishwasher

Miele Dishwasher F12: Water Inlet Blocked or Restricted (Meaning, Causes, Fixes)

Q: What does Miele Dishwasher F12 mean?

F12 on a Miele dishwasher is a water inlet fault: the machine isn't getting enough water at the start of a fill. Miele's own fixes come first and are things you can do yourself: open the faucet or shutoff valve fully, clean the small plastic filter in the inlet hose connection, and take any kinks out of the hose. Miele also says the flow pressure must be at least 7.25 psi (0.5 bar). If F12 keeps coming back after that, book a repair, because the inlet valve, the flow meter or the electronics may be at fault. Miele's support pages in the US, Canada, UK and Australia describe F12 as "Fault F12 (water inlet)": "The water inlet is blocked or restricted." They list four causes in order: the faucet is not open, the inlet filter is soiled, the water inlet hose is kinked, or the flow pressure at the water connection is lower than 7.25 psi (0.5 bar). Miele's G 1/G 2 Series technical manual, written for technicians, calls F12 "Water intake fault at start of step." The flow meter counts the water coming in, and if it doesn't see enough pulses, the dishwasher keeps retrying the fill at intervals for up to an hour, running the drain pump now and then so it can't overflow, and then sounds the buzzer for 2 minutes. That manual's causes start with the same supply problems, then move on to the flow meter not sending pulses, an open circuit in its wiring, a clogged filter in the WaterProof System valve, and a defective water inlet valve. F12 is a different fault from F18 (water intake valve fault), where water comes in when the valve should be shut, and from F11, a drainage fault.

Reviewed 2026-10-26 · Based on 5 manufacturer & service sources

What the code means

Miele's support pages in the US, Canada, UK and Australia describe F12 as "Fault F12 (water inlet)": "The water inlet is blocked or restricted." They list four causes in order: the faucet is not open, the inlet filter is soiled, the water inlet hose is kinked, or the flow pressure at the water connection is lower than 7.25 psi (0.5 bar). Miele's G 1/G 2 Series technical manual, written for technicians, calls F12 "Water intake fault at start of step." The flow meter counts the water coming in, and if it doesn't see enough pulses, the dishwasher keeps retrying the fill at intervals for up to an hour, running the drain pump now and then so it can't overflow, and then sounds the buzzer for 2 minutes. That manual's causes start with the same supply problems, then move on to the flow meter not sending pulses, an open circuit in its wiring, a clogged filter in the WaterProof System valve, and a defective water inlet valve. F12 is a different fault from F18 (water intake valve fault), where water comes in when the valve should be shut, and from F11, a drainage fault.

Likely causes

The faucet or shutoff valve feeding the dishwasher is closed or only partly open (Miele's first cause)
A dirty or blocked plastic filter in the screw connection of the water intake valve at the faucet
A kinked or looped water inlet hose
Household flow pressure below 7.25 psi (0.5 bar); the technical manual says supply pressure below 14.5 psi should be checked by a specialist
A defective water inlet valve (the WaterProof System valve) that isn't opening
The flow meter not sending pulses (reed switch, its circuit board or plug), or an open circuit in its wiring
Less often, a fault in the water diverter or the electronic board

Safe DIY checks

⚠ Before you start

Unplug the dishwasher and close the faucet before unscrewing the inlet connection. The plastic housing at the faucet end contains an electrical valve, so never put it in water. Valve, flow-meter and board checks are for a technician.

Make sure the faucet or shutoff valve feeding the dishwasher is fully open.
Straighten the water inlet hose and remove any kinks or loops. Keep an eye on those spots afterward, since Miele says the plastic can weaken and tear; a damaged hose has to be replaced.
Clean the inlet filter. Switch the dishwasher off, unplug it and close the faucet. Unscrew the water intake valve from the faucet, remove the seal, then pull the plastic filter out by its bar with combination or needle-nose pliers.
Rinse the plastic filter under running water. Don't dip the plastic housing at the water connection in water; Miele warns it contains an electrical valve.
Put the filter and seal back so they're seated correctly (the filter must go back in), screw the connection securely onto the faucet, and open the faucet slowly. Tighten the connection if it drips.
If other taps in the house are weak too, have a plumber or the building manager check the supply. Miele says flow pressure must be at least 7.25 psi (0.5 bar).
Switch the dishwasher back on and start a program. If F12 returns with the water fully on, note the model and serial number from the rating plate on the edge of the door and contact Miele Service (US 888-996-4353).

🛠 When to call a pro

F12 comes back with the faucet open, a clean filter and a straight hose: a technician checks the inlet valve. Miele's technical manual has them start a program and feel the valve housing during the fill step; if it vibrates, the valve is getting power and gets replaced, and if not, they trace power from the valve connector back to the electronic board.
The valve opens and water flows but F12 persists: the technician checks the flow meter's reed switch, its plug and its wiring. The manual's test is to pass a magnet over the reed switch; if that produces a pulse, the water diverter is replaced, and if not, the reed switch is.
The flow meter reads pulses and F12 still shows: the manual says to replace the electronic board.
The dishwasher is under warranty or extended cover: use Miele Service first.

Parts that commonly fix it

Always match the part number to your exact model.

⚙

Dishwasher water inlet valve

Replaced when it gets power but doesn't open. On many Miele models it sits in the WaterProof hose at the faucet end, so match the part to your model number or let Miele Service fit it.

Search eBay →

⚙

Dishwasher inlet hose

Only if the hose is kinked so badly it has cracked or torn. Miele says a damaged hose must be replaced; on WaterProof models the hose and valve are one assembly.

Search eBay →

⚙

Multimeter

For a technician's checks on the valve power, the flow meter wiring and plug connections with the machine unplugged.

Search eBay →

Sources

Last reviewed 2026-10-26. Always confirm against the manual for your exact model number.

Miele Dishwasher F12: Water Inlet Blocked or Restricted (Meaning, Causes, Fixes)

What the code means

Likely causes

Safe DIY checks

🛠 When to call a pro

Parts that commonly fix it

Dishwasher water inlet valve

Dishwasher inlet hose

Multimeter

Related codes

Sources