Sometimes the dishwasher drain pipe is fine, but the sink drain it feeds into is blocked. If the sink is draining slowly, the dishwasher cannot push water out either.
Run an empty cycle with a dedicated dishwasher cleaner or a bowl of white vinegar on the top rack once a month. dishwasher drain pipe blocked
Open the cabinet under your kitchen sink. You will see a ribbed rubber hose connecting your dishwasher to the sink plumbing (or directly to the disposal). It is usually secured with a hose clamp. Sometimes the dishwasher drain pipe is fine, but
Cheap detergents can cause "soap scum" buildup that narrows the pipe over time. Open the cabinet under your kitchen sink
If the hose is blocked, you can try banging on it gently to dislodge the debris. For stubborn clogs, you may need to disconnect the other end of the hose (at the dishwasher connection) and flush it out with high-pressure water from a garden hose or a faucet.
Before you take the machine apart, look for these tell-tale symptoms: Standing water at the bottom of the tub after a cycle.
If you have a small cylinder on your sink deck (the air gap), unscrew the cap and check for debris or buildup. Step 2: Inspect the Drain Hose