Dishwasher Not Draining? Here's What's Causing It

Standing water in the bottom of the dishwasher after a cycle is one of those problems that has many possible causes — most of them cheap, a few of them not. Here's the order I check things in when I get to a customer's house in Mountain View or Palo Alto for this exact call.

Step 1: clean the filter

Almost every modern dishwasher has a removable filter at the bottom of the tub. Twist it counter-clockwise and pull it out. If it's full of food debris, glass shards, or stickers from canned tomato cans (the most common single-item cause we see), you've found your problem. Clean it under the tap, replace it, run a cycle.

Step 2: check the drain hose

Pull out the dishwasher carefully — most are just held in by two screws under the counter lip — and look at the corrugated drain hose that runs to the disposal or air gap. If it's kinked, that's your fix. If you've recently replaced the disposal and the installer didn't punch out the dishwasher knockout plug, that's a guaranteed no-drain situation. (We see that one ALL the time after a DIY disposal swap.)

Step 3: clean the air gap

On Bay Area homes, code requires either an air gap on the countertop or a high-loop in the drain hose. The air gap is the little chrome cylinder next to the faucet. Pop the cap off and check for sludge. Two minutes of cleaning fixes a lot of "won't drain" calls.

Step 4: test the drain pump

If the filter is clean and the hose is unobstructed and you can still hear the pump running but nothing is moving, the impeller may be cracked or the pump motor is shot. This is where it stops being a DIY job — the pump is below the motor on most modern units and getting to it usually means partially disassembling the bottom of the dishwasher.

Step 5: control board / drain solenoid

Older Whirlpool, KitchenAid, and Bosch units use a solenoid that opens the drain valve. If it's stuck, the cycle will finish normally but no water will leave the tub. On newer units it's usually a bad relay on the control board.

If steps 1–3 don't fix it, you're at the point where the right move is a tech with a meter and the right replacement parts on the truck. We do dishwasher repair same-day across the Bay Area, with a 3-month warranty on parts AND labor.

Standing water that won't go away? Call (650) 691-3065 and we'll get out today.