Miele Dishwasher Maintenance: The Filter Nobody Has Lifted

Miele builds dishwashers to a service interval rather than to a failure point, which is a real engineering distinction and it changes what goes wrong with them. These machines rarely break. They gradually stop working properly because something routine was never done, and then they present with a symptom that looks like a broken part.

The filter is the centre of it.

The filter you may not know exists

Under the lower spray arm there is a coarse screen, and under that screen sits a finer filter assembly that lifts out with a quarter turn. A great many owners have never lifted it. The machine does not complain, it does not throw a code, and it will keep running for years on a filter that is half blocked.

What happens instead is that wash quality declines so slowly nobody can say when it started. Glasses come out gritty. Something on the top rack is not getting clean. The natural conclusion is that the spray arm is blocked or the pump is weakening, and neither is true — the machine is recirculating water it cannot properly clear.

Lift it out, rinse it under a tap, brush the mesh gently, put it back. That is the whole job, and on a machine that has never had it done the difference in the next cycle is obvious.

Spray arms, while you are in there

Both arms come off without tools. Hold each one up to a light and look through the jets. Anything blocked clears with a toothpick or a straightened paperclip.

Nothing harder than that goes near a spray jet. A drill bit or a needle file will widen the hole permanently, and a widened jet sprays at the wrong pressure in the wrong direction for the rest of the machine’s life. It cannot be undone.

The wet-dishes question, settled

This is the most common Miele complaint we are called about and it is not a fault.

These machines use condenser drying: the load’s own residual heat evaporates the water, which condenses on the cool stainless tub wall and drains away. There is no heating element blasting the load dry. It is quieter, it uses less energy, and it is gentler on plastics — and it leaves plastics damp, because plastic holds very little heat of its own.

If dishes are coming out wet and they always have, the machine is working correctly. Open the door for ten minutes at the end of the cycle and the residual warmth finishes the job. If dishes used to come out dry and now do not, that is different, and worth a look.

What actually fails

Setting maintenance aside, three things genuinely break on these:

• The drain hose kinked behind the machine. Almost always the result of the appliance being pushed back too hard during a kitchen job. It presents as a drainage fault and is a plumbing one.
• The waterproof system tripping. Water in the base tray triggers a float, which shuts off the supply. The protection has done its job; what needs finding is where the water came from.
• The door seal, eventually. Decades in, and usually announced by a damp patch at one lower corner rather than by anything dramatic.

A rinse-aid note

Miele machines assume rinse aid is present and their drying performance is built around it. A machine running dry of rinse aid will leave spots on glass and more water on everything, which reads as a decline in performance. It is worth checking the reservoir before concluding anything about the machine.

When it is worth calling us

If wash quality has not recovered after the filter and the spray arms have been cleaned properly. If the waterproof system has tripped. If the machine will not start with the door plainly shut, which is usually the door latch microswitch rather than anything expensive. And if it drains partially — that pattern points somewhere specific and it is worth reading the code alongside the state of the sump rather than guessing.