Miele F12 fault codewhat it means and how to fix it
The water inlet is blocked or restricted. Miele use the same wording for F13 and F15, give F173 the same filter procedure, and warn that the hose connection houses an electrical valve.
Take care
What F12 means
Miele give F12 as the water inlet being blocked or restricted, and they publish word-for-word the same article for F13 and F15; F173 gets the same stopcock check, the same inlet-filter procedure and the same low-pressure cause, minus the section on a kinked hose. So if you have one of those, this is your page. It is a code Miele expect owners to resolve, and the checks are the ones they list: the stopcock, the inlet filter in the connection, the hose, and finally the flow pressure at the connection, which Miele say must not be lower than 50 kPa (0.5 bar).
There is one Miele-specific warning that belongs here and that people get wrong because the part does not look electrical. Miele state that the plastic housing of the water connection contains an electrical valve, and that the housing must not be dipped in water, under a heading about risk of electric shock from mains voltage. That is the chunky plastic block where the hose meets the tap. It is a mains-voltage component in a plumbing-shaped package, and it should not be submerged, cut or improvised with.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Stopcock or tap not fully open | Free to eliminate, and the first thing to check if any plumbing work has happened recently. | Common |
| Inlet filter soiled | The small plastic filter inside the screw connection where the water intake valve meets the stopcock, silted with grit from the mains. The most common genuine cause and cleanable by hand. | Common |
| Inlet hose kinked | Usually crushed when the machine was last pushed back into its housing after cleaning or repair. Miele add that a hose that has been kinked may weaken and tear at that point later, and must be replaced if damaged. | Common |
| Flow pressure too low | Miele’s figure is a flow pressure at the water connection below 50 kPa (0.5 bar): a weak or shared supply, or a partly closed isolation valve upstream. The machine is fine; the supply is not, and Miele’s instruction is to contact a plumber or the facility manager. | Occasional |
What to try yourself
Check the stopcock feeding the machine is fully open — right off and right on again rather than judging by the handle. Miele list this first.
Pull the machine out enough to see the hose along its length and remove any kinks or loops. Miele say to keep an eye on those points afterwards, because the plastic may have weakened and can tear; a damaged inlet hose must be replaced, which is a Miele job.
Clean the inlet filter Miele’s way: switch the dishwasher off and unplug it, close the stopcock, unscrew the water intake valve from the stopcock, take the seal out of the screw connection, grip the plastic filter bar with pointed or combination pliers and pull the filter out, rinse it under running water, then refit the filter and seal, checking both are seated correctly.
Miele warn of risk of electric shock here: the plastic housing of the water connection contains an electrical valve and must not be dipped in water. Clean the filter, not the housing.Screw the connection securely back onto the stopcock and turn the stopcock on slowly. If water drips from the joint, tighten it. Miele are explicit that the filter must be put back after cleaning.
Restore power and run a programme. If the tap, hose and filter are all clear and the code returns, the remaining cause Miele list is flow pressure at the connection below 50 kPa (0.5 bar), which is a plumber’s job rather than an appliance fault.
Get a qualified appliance engineer to look at your Miele F12
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£220
Time on site
30 minutes
Usually free. A replacement Miele inlet valve and hose assembly is typically £110 to £200 fitted.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Miele fault codes
- F11Get it checkedWater left standing in the cabinet because the machine cannot drain. Miele treat this as an owner job and walk you through the drain pump.Related: same brand
- F70Stop — call an engineerThe Waterproof System has activated. Miele give the clearest emergency instruction of any dishwasher manufacturer — close the stopcock, switch off, unplug, call.Related: same brand
- F69Get it checkedThe circulation pump is blocked. Miele distinguish this from a pump fault, and a blockage is yours to clear.Related: same brand
- F52Usually simple to fixA sensor has detected too much foam and stopped the programme. Nothing is broken — the machine is protecting itself from suds.Related: same brand
- F86Usually simple to fixThe salt reservoir flap in the door is not closed. On Miele machines with the salt container in the inner door, a lid left open after a refill stops the programme. Ten seconds to fix.Related: same brand
Own a Miele dishwasher? Save it and its codes come first next time.
Related guides
Common questions about Miele F12
I have F13, F15 or F173 rather than F12. Is this the right page?
Yes. Miele publish F13 and F15 as word-for-word copies of the F12 article — the water inlet is blocked or restricted — and F173 with the same stopcock check, filter procedure and low-pressure cause. Four codes, one answer.
Why can I not just rinse the whole hose connection under the tap?
Because Miele state the plastic housing contains an electrical valve and must not be dipped in water, under an electric shock warning. It looks like plumbing and it is partly electrics. Clean the filter itself and leave the housing dry.
What if everything is clear and it still shows?
Then the inlet valve or the supply is at fault rather than a blockage, and Miele’s guidance is to contact Customer Service if the fault persists. You will have eliminated the free causes, which shortens the visit.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer support portal
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.