If your dishwasher is filling slowly, running long, or leaving dishes wet, most homeowners reach for the detergent or the spray arm first. Before you do, check the water inlet screen. Many dishwashers have a small mesh screen where the supply line enters the machine, and sediment from your home plumbing or from work on the street can collect there. In St. Louis, where many homes have older plumbing, that small screen can catch more than you might expect.

This guide covers how to find the screen, how to clean it, and what to check if the problem stays after cleaning. The steps fit a typical built-in or freestanding dishwasher. Your model may differ, so check the owner's manual if anything looks unfamiliar.

What the screen does

Water enters the dishwasher through a supply hose connected to the inlet valve, usually at the lower back or under the front of the unit. Many inlet valves have a fine screen at the connection point or inside the valve body. Its job is to catch small particles before they reach the valve and the fill path. When it clogs, the machine gets less water, fills more slowly, or can fail to finish a cycle.

A salt-free water conditioner does not remove sediment. It works on a different problem, so a screen can still clog even in a home that already has a conditioner. Sediment capture and scale control are separate jobs.

Signs the inlet may be restricted

  • The fill takes longer than usual, or the machine pauses before it starts filling.
  • Cycles run longer than the manual describes.
  • Dishes come out wet, or the wash water looks low in the tub.
  • A fill or water supply error code appears, if your model shows codes.
  • Faucets elsewhere in the house run normally, which points toward the dishwasher side.

Before you start

  1. Turn off the dishwasher at its control panel, then unplug it or switch off its breaker.
  2. Shut off the water supply valve under the sink where the dishwasher hose connects. If there is no valve there, shut off the main water to the house and open a faucet to relieve pressure.
  3. Set a towel and a shallow pan under the connection. Some water will drain out when you disconnect the hose.

Clean the screen

  1. Disconnect the supply hose from the inlet valve. The fitting is usually hand tight, so start by turning it by hand.
  2. Look into the valve opening or the hose end for a small mesh screen or plastic filter. Note whether it sits in the hose or in the valve body.
  3. Pull the screen out gently. Rinse it under running water, working from the clean side so debris is pushed out the way it came in.
  4. Use a soft brush to remove grit. Avoid sharp tools that could tear the mesh.
  5. If the screen is cracked, torn, or badly bent, replace it rather than trying to keep using it.
  6. Reseat the screen, reconnect the hose by hand, then snug it gently with a wrench. Do not force it.

While the hose is off, inspect it too. Look for kinks, flattened sections, cracks, or bulges. A hose in that condition should be replaced, even if the screen was the only clog you found.

Test the fill

Turn the water back on slowly and watch the connection for drips. Restore power, then run a short rinse cycle and listen to the fill. A clean screen should bring the fill back to normal. Check the connection again after the first fill and once more after the cycle finishes.

When the screen is not the problem

If the fill is still slow after cleaning, the restriction may be upstream, at the shutoff valve, in the supply line, or inside the machine. The inlet valve itself can wear or fail. Older homes in St. Louis sometimes have galvanized supply pipe that can shed flakes over time, which can restrict flow at several fixtures. If water pressure is low at other faucets too, check it at an outdoor hose bib with a gauge before you assume the dishwasher is at fault.

Call a licensed plumber or appliance technician if you see water on the floor after reconnecting, if the inlet valve hums without filling, or if a fill error returns after cleaning. Write down what you already checked, since that saves time and helps the technician start in the right place.

Keep it from clogging again

  • Run a rinse cycle now and then and listen for a normal fill.
  • Check the supply hose each time you move the dishwasher or the cabinet around it.
  • After any plumbing work on your street or in your home, expect more sediment for a while and check the screen sooner than usual.