Dishwasher Problems Sorted by Symptom

Most dishwasher complaints fall into a handful of groups: water left in the bottom, dishes that come out wet, dishes that come out dirty or spotted, water on the floor, and a machine that won't start or quits partway. Each group has its own short list of causes, and several of them take five minutes and no tools to fix. Here is how to work through them.

Power and water first

Before you reach into the tub or under the sink, cut the power. Some dishwashers plug into an outlet under the sink, others are hardwired to a wall switch or straight to a breaker. If you aren't sure which, turn off the breaker. The water supply valve is usually under the sink as well, on the hot-water line.

Water sitting in the bottom

A little water in the sump below the filter after a cycle is normal on many models. Standing water above the filter, or dirty water covering the floor of the tub, is not.

Work through these in order:

1. The filter. Most current dishwashers have a removable cylinder filter in the bottom of the tub, under the lower spray arm. Twist it out, rinse it under the tap, and scrub the fine mesh with a soft brush. A clogged filter is the usual reason for standing water and poor cleaning, and the manual will suggest how often to check it.
2. The drain hose. Follow it under the sink. A hose pinched behind the trash can or crushed during a cabinet repair will stop drainage completely.
3. The disposal connection. When the drain trouble started right after a new garbage disposal went in, the knockout plug in the disposal's dishwasher inlet may never have been removed. It's a classic installation slip.
4. The air gap. If there is a small chrome cap on the countertop near the faucet, lift it off and clear any debris inside.
5. The sink drain. If the kitchen sink itself drains slowly, the dishwasher is pumping into a clogged line. That's a plumbing problem.

If all of those are clear and the dishwasher still holds water, the drain pump or its check valve is the likely suspect. You may hear the pump hum without moving water.

Dishes still wet at the end

Dishwashers dry in two ways. Some use a heating element and a heated-dry option; many current models, especially European designs, use the heat stored in the dishes from a hot final rinse and let the water condense on the stainless tub walls. Both depend on the same things:

• •Rinse aid. It helps water sheet off instead of beading. On condensation-dried machines, an empty dispenser alone can leave everything wet.
• •The drying setting. Heated dry may be turned off, or an eco cycle may be selected that shortens drying.
• •Plastic. Plastic holds little heat and almost never comes out fully dry. That's normal.
• •Unloading order. Empty the bottom rack first, so water from cupped glasses on the top rack doesn't drip down onto dry plates.

On a humid summer day, with the kitchen air already holding a lot of moisture, drying is slower. Cracking the door open at the end of the cycle helps. A machine that used to dry well and suddenly doesn't, even with rinse aid, may have a failed heating element or vent.

Dishes dirty, gritty or spotted

Start with the filter, then look at the spray arms. Pull them off (most twist or pop off) and look at the small holes. Food bits and mineral scale block them, and a blocked arm leaves a section of the rack unwashed. Clear the holes with a toothpick and rinse the arm.

Tampa's water is hard, which means mineral scale builds up over time on the spray arms, the heating element and the inside of the tub. It also shows up as a white film on glasses. A dishwasher cleaner containing citric acid, run on an empty machine, removes much of it. Rinse aid helps with spotting.

A few other checks:

• •Run the kitchen tap until it's hot before starting a cycle. The first fill is usually water that has been sitting in the line.
• •Check the loading. A tall pan or cutting board can stop the spray arm from turning or block the detergent door from opening.
• •Use fresh detergent. Powder and pods that have sat in a humid cabinet can clump and fail to dissolve.

Water on the floor

Turn off the power and look for where the water first appears.

• •Under the door, with suds. Someone used hand dish soap. Run a rinse cycle with no detergent, or a few cycles if needed, until the suds are gone.
• •Under the door, no suds. Check the door gasket for food stuck in it, a tear, or a flattened section. Check that the dishwasher is level; a tilted tub can push water toward the door.
• •Under the machine. The inlet valve, drain hose connection, pump seal or a cracked tub can all leak. Turn off the water supply and call.

In a condo or apartment, a slow leak under a dishwasher can reach the unit below. Shut off the water at the valve and tell your building management early, as many associations have rules about water damage.

Won't start or stops mid-cycle

• •The control lock (often a key or padlock symbol) disables the buttons. The manual explains how to turn it off.
• •Delay start may be on.
• •The door latch must engage fully. A latch that doesn't click, or a door that pops open, means a latch or strike problem.
• •A flashing light or code usually points to a specific fault: water supply, drain, heating or a leak sensor. Look it up for your model before resetting.

If a dishwasher tripped its breaker or GFCI outlet, reset it once. If it trips again, leave it off and call.

When to have it looked at

If the filter, hose, spray arms and settings all check out and the problem continues, the cause is likely a pump, valve, sensor, heating element or control. A technician checks each of those in your kitchen, names the one at fault, and gives you a price to accept or decline before any work. If the repair doesn't make sense for the age of the machine, we'll say so.

See the dishwasher repair page, or for Bosch specifics, our Bosch dishwasher guide. You can also book a visit online.

Common questions

How do I tell mineral film from etching on glasses?

Let one hazy glass sit in plain white vinegar for five minutes or so. If the haze comes off, it is mineral film from hard water. If it stays, the glass surface is etched, which can't be undone and often comes from too much detergent in soft or softened water.

Should I run the dishwasher with the heated dry option?

It gives drier dishes, especially plastics, and uses more energy. Rinse aid and leaving the door open at the end of the cycle get most of the way there without it.