The Filter Whirlpool Files Under Not Draining, and What That Tells You

How often should I clean my Whirlpool dishwasher filter? Sooner than you think

Every four to six weeks if the machine runs daily. Twice a year is the absolute floor, and twice a year in this water is already a compromise.

That is a shorter interval than most manuals suggest, and the reason is not the appliance. It is that Miami water is hard, a mineral film builds on the mesh, and everything that lands on the mesh afterward sticks to that film instead of rinsing off it.

Two complaints, one cause

People call about two things that sound unrelated.

*The plates come out with grit on them.* And: *there is always a little water in the bottom, and it has started to smell.*

They are usually the same problem.

A dishwasher recirculates its wash water. The same water is thrown at the dishes, drains back through the filter into the sump, and is pumped up and thrown again. Everything it picks up on the way has to be caught somewhere, and the somewhere is the filter.

When the filter packs, the pump can no longer draw clean water. So the machine is spraying its own soil back onto the load. That is the grit.

The same restriction slows the drain. So water sits in the sump between cycles. Warm, still, and carrying what the filter did not hold. That is the smell.

Whirlpool's own support base makes the connection without comment: *water remains in the filter area* is filed under not draining. The maker is telling you where standing water comes from, in the section title.

The change nobody announced

This deserves its own paragraph, because it is why so many owners of this make have never done the job.

The previous generation of dishwashers ground food waste up. A hard food disposer sat in the sump doing what a garbage disposal does — noisily — and the owner's entire maintenance obligation was to not put a teaspoon down there.

The current generation catches the soil instead and holds it in a removable filtration system. That is why these machines are quiet enough to run while you are in the room. It is a better design in every respect but one: it created a chore, and the chore was not on the delivery driver's list of things to mention.

So there is a large population of perfectly good Whirlpool dishwashers in South Florida, five and eight and ten years old, whose owners have never once taken the filter out — and who conclude, entirely reasonably, that the machine has got worse with age.

What comes out of one

Be prepared. A filter in a household that puts plates in without a rinse holds a compacted mat of starch, fat and fiber, and in hard water that mat is bound together by mineral scale.

Under it, in the sump recess, is the other half of the story: glass chips from a broken tumbler somebody thought they had swept up, olive and cherry pits, fruit stickers, and the paper labels off jars. None of that is stopped by a filter mesh. It sits in the recess and waits.

Glass grit is the one that costs money. It gets past the filter when the filter is not locked down properly, reaches the pump, and takes the impeller and the seal with it. That is the difference between a five-minute job at the sink and a drain-and-pump repair.

The half people leave behind

There are two parts, and almost everybody who has done this once has only done half of it.

The raised cylinder in the middle is the obvious one. It turns about a quarter turn counterclockwise and lifts straight out. When it will not move, the reason is nearly always that somebody is pulling up instead of twisting.

Underneath it there is a flat screen, lying in the floor of the tub. On some machines it lifts out separately, on others it is joined to the cylinder. That flat screen is the fine filter, and it is the one that actually restricts. A cylinder rinsed under the tap and put back over a blocked screen changes nothing, and the owner concludes that the filter was not the problem.

Take both. Wash both. Look at the sump while they are out.

Putting it back is the part that matters

The screen seats first, and it has to lie flat with nothing standing proud of the tub floor. Then the cylinder drops into the center and turns clockwise until it stops.

Then tug it. It should not lift.

A cylinder left crooked or unlocked does not merely filter badly — it lets the wash water bypass the filter completely, which is worse than having no filter at all, because everything now goes to the pump. If the cylinder fights you on the way back, the screen underneath is not seated. Take both out and start again.

Ten minutes twice a year that are worth more than any of this

While the filter is out, two more things are free.

Run a hot cycle with the machine empty, with a dishwasher cleaner or a cup of white vinegar on the top rack. In hard water this keeps the scale from setting on the mesh in the first place, and it makes the next filter clean easier than this one.

Check the spray arm holes. Take the lower arm off — most of them unclip or unscrew by hand — and hold it up to the light. Blocked holes are the second cause of gritty plates, and the things blocking them come from the same place as everything in your filter.

If the plates are still gritty after all of that, then the machine has a wash performance problem rather than a maintenance one, and that is a different conversation with a pump, a spray arm bearing or a water inlet in it.