The Most Likely Causes
Listed in rough order of how often they turn out to be the culprit — not a diagnosis of your specific machine. Work top-down: the cheap, free checks first, then test before you buy anything.
Clogged filter basket
The cylindrical filter in the tub floor traps food. When it clogs, water can't drain. Twist it out, rinse it, and clear the sump — free, and the most common fix.
New disposal knockout plug left in
If a garbage disposal was recently installed, the drain line often connects to it — and there's a knockout plug that MUST be punched out. Miss it and the dishwasher can never drain.
Kinked or clogged drain hose
The hose under the sink can kink or clog at the high loop / air gap. Straighten and clear it before assuming a pump.
Failed drain pump
If everything upstream is clear and it still won't drain, the drain pump has failed. It's under the tub and replaceable with basic tools.
Test → Estimate → Test
Good techs don't swap parts and hope. They test, price it out, then confirm. Do the same and you won't buy the wrong part — or pour money into a machine that isn't worth it.
1 · Test before you buy
Confirm the suspect part is actually bad — a multimeter continuity check, or a clear visual like a split element or a cracked gasket. Never replace on a guess; that's how the returns pile up.
2 · Estimate honestly
Add up the parts plus your time and compare to a new unit. A cheap part in a well-built machine is a yes. A pricey control board in an old one may not be. Be honest with yourself here.
3 · Test again after
Once it's installed, run a full cycle and confirm the fix before you button everything back up. Two minutes now beats taking it apart twice.
The Tools to Test + Fix With
You don't need a shop full of tools — you need these. The multimeter is the one that pays for itself the first time it stops you buying the wrong part.
Digital multimeter
Test a suspect part for continuity BEFORE you buy — the single best way to avoid replacing the wrong thing.
🔎 On Amazon →Nut driver set (¼" + 5⁄16")
Most appliance panels are held on with ¼" and 5⁄16" hex screws.
🔎 On Amazon →Screwdriver set (Phillips/flat/Torx)
Covers the odd panel screw and Torx fasteners many brands use.
🔎 On Amazon →The Likely Parts — Test First, Then Buy
These are the usual suspects for this symptom, cheapest-and-easiest first — not a diagnosis of your exact unit. Test to confirm the part's actually bad first. For each one you get both options: the genuine OEM part sourced through us and shipped to your door, or a budget aftermarket part you grab on Amazon. Your call.
No part — just clean it
Only replace if the mesh is torn; usually a rinse is all it needs.
✅ No part needed — you can DIY this freeNo part — punch out the plug
Look inside the disposal's dishwasher inlet nipple for the plug.
✅ No part needed — you can DIY this freeDishwasher drain hose
Replace only if split; usually just needs clearing.
Dishwasher drain pump
Buy for your exact model — pumps aren't universal.
Prices shown are typical aftermarket ranges and vary by brand and model — genuine OEM is priced by quote when you request it. Amazon links open a search so you can match your exact model number before buying; as an Amazon Associate, Appliance Ant may earn from qualifying purchases at no extra cost to you. Always confirm the part fits your model.
Safe to Try · Know the Risk · Call a Pro
General guidance, not professional advice. Always unplug the appliance (or shut off the gas/water) before you check anything. If it feels beyond you, that's exactly when to get a pro.
✅ Safe to try yourself
- Twist out and rinse the filter; scoop the sump.
- If a disposal was just installed, confirm the knockout plug was removed.
- Check the drain hose under the sink for kinks and clogs.
⚠️ Doable — know the risk
- Drain pump or check-valve replacement — doable, but shut off power at the breaker and the water supply, and expect water in the base pan.
🛑 Call a pro — don't touch this
- A leak reaching the control board or the wiring under the tub.
- Any repair where you can't safely cut power and water first.
The Honest Call
Usually worth it. The top causes are free (filter, knockout plug) and the drain pump is $30–90. A new dishwasher is $500+ plus install. Draining problems are the cheapest, most beginner-friendly dishwasher repair.
In Middle Tennessee or Louisiana?
Don't want to DIY it? Our own family of technicians will come fix it — honest flat pricing, usually same-day, 4.5★ from 1,000+ neighbors.
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