Open the door and there's a pool in the bottom. Good news: this is almost always a cheap problem — a quick cleaning, or a knockout plug left in on a newly-installed garbage disposer. Below are the causes in the order we check them, the actual tests, the parts and honest prices, and the safe checks you can do first.
New to multimeter testing? Read how to diagnose any appliance — power → switch → load first — the tests below all use it.
Food, glass, and labels block the bottom filter and the pump inlet so water can't leave.
Test it yourself: Remove the bottom rack, twist out the cylindrical filter at the bottom, and rinse it. Clear any debris from the sump (the well underneath) and the pump inlet by hand.
🔩 Likely part: no part — cleaning — $0
When a dishwasher drains into a new garbage disposer, the disposer's dishwasher inlet ships with a solid knockout plug. If it wasn't knocked out during install, water has nowhere to go. Extremely common after a disposer swap.
Test it yourself: If a disposer was recently installed, look at the disposer's dishwasher inlet nipple. Knock the plug out with a screwdriver + hammer and fish the disc out of the disposer so it doesn't cause a new clog.
🔩 Likely part: no part — $0
The drain hose under the sink can be pinched, or lack the high loop/air gap that stops dirty water from siphoning back into the tub.
Test it yourself: Check the hose under the sink for kinks and clear it. Make sure it loops up high (secured near the underside of the counter) or runs through an air gap before going down to the disposer/standpipe.
🔩 Likely part: drain hose (only if kinked/split) — $15–35
Debris jams the pump, or the pump motor fails, so it can't move water even when the path is clear.
How a tech tests it: After cleaning, if it still won't drain: with power off, a tech checks the pump inlet for a jam and tests the pump motor for continuity — an open reading (OL) means the pump is dead and needs replacing.
🔩 Likely part: drain pump — $30–80
Less common: a stuck drain/check valve, or a control board that never triggers the drain step.
How a tech tests it: Diagnosed by a technician after the cheap causes are ruled out — usually a continuity/actuation test on the valve or board.
🔩 Likely part: drain valve / control board — $20–120
Most no-drain dishwashers are the cheapest repair there is — often just cleaning or a knockout plug, and even a drain pump is typically $30–80 in parts. Almost always worth fixing. Send us a 10-second video and we'll tell you if it's a DIY or a part.
In Middle Tennessee or the Baton Rouge area? We'll come to you, same-day. Anywhere else in the U.S.? Send a 10-second video, a real technician tells you exactly what's wrong for $50 (credited toward the repair), and we ship you the exact part — or walk you through the DIY fix. 24/7 — text, call, or upload anytime.
A little is normal; a full pool means the drain failed. Usual causes: a clogged filter/sump, a new-disposer knockout plug left in, a kinked hose or missing high loop, or a bad drain pump. Clean the filter and check the disposer plug first.
Almost certainly the knockout plug in the disposer's dishwasher inlet was never removed. It ships sealed; you have to knock it out and remove the disc. 5-minute fix that's missed all the time.
If the filter, hose, high loop, and disposer plug are all clear and it still won't drain, the pump is the suspect — a tech confirms with a continuity test (open = dead).
Often yes — cleaning the filter/sump, knocking out a disposer plug, and clearing a kinked hose are all safe with the power off. A failed pump or valve is a technician repair.
Almost always — it's typically the cheapest repair on the appliance. We'll confirm the exact cause from a short video.