Symptoms: Not Draining

Dishwasher Not Draining But No Blockage? Here’s What’s Actually Wrong

If you’ve already checked the filter, hose, and air gap and it still won’t drain, the problem is almost always the drain pump itself or the control board that powers it.

Risk: Moderate
Difficulty: Intermediate
Estimated time: 30 to 60 minutes

Before you start

Unplug the appliance, shut off the water supply if relevant, and stop immediately if you smell burning. If in doubt, call a qualified professional.

On this page

Tools needed
Probable causes
First checks
Step-by-step diagnosis
Mistakes to avoid
When to stop
Parts involved
When to call a professional

If you’ve already ruled out the filter, drain hose, air gap, and disposal knockout plug covered in our main not-draining guide and water is still sitting in the tub, the blockage isn’t the issue anymore. Something electrical or mechanical inside the pump assembly is. This page picks up exactly where that one leaves off.

This page is part of our full dishwasher troubleshooting guide. For the complete pump testing and replacement walkthrough, see our drain pump guide.

Quick Diagnosis Table

Cause	Likelihood	Difficulty	Typical Part Cost
Failed drain pump motor	Very likely	Moderate	$25–75
Loose or corroded pump wiring	Likely	Moderate	$0–10
Control board not powering pump	Possible	Professional recommended	$80–200+
Failed drain solenoid	Possible	Moderate	$20–50
Jammed impeller	Possible	Moderate	$0 — clearing only
Stuck float switch	Rare	Easy–Moderate	$10–20

Repair or Replace?

A drain pump replacement is a reasonable DIY repair on most models and stays well under $75 in parts. A control board is the one component on this page worth pricing carefully: $80–$200 in parts plus labor if you hire it out, which starts to approach a meaningful fraction of a new mid-range dishwasher on a unit that’s already 8+ years old.

Pump and board locations vary by brand: Whirlpool and KitchenAid (which share platforms) mount the pump differently than Bosch or Samsung. Brand-specific guides are on the way.

Frequently Asked Questions

My multimeter shows the pump is fine — what else could it be?

Move on to testing continuity from the control board's drain output to the pump connector. If the board isn't sending power, the pump can be perfect and still never run.

How much does a professional charge to diagnose a no-drain dishwasher?

Typical diagnostic visits run $80–150 in most U.S. markets, often credited toward the repair if you proceed with the same company.

Can a bad drain pump cause the whole dishwasher to stop mid-cycle?

Yes — on many models the control board waits for a successful drain confirmation before proceeding, so a dead pump can make the entire cycle appear to hang.

Is it worth replacing the pump myself, or should I hire someone?

If you're comfortable working with a multimeter and following a wiring diagram, a pump swap is a reasonable weekend repair. If diagnosis points to the control board, most people are better off hiring it out.

Why did my dishwasher drain fine yesterday and not today?

Intermittent draining often points to a wiring connector that's making contact only sometimes — reseat the pump connector firmly and check for corrosion before assuming the pump itself has failed.

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

Tools needed

Multimeter
Nut driver or screwdriver set
Towels
Flashlight
Phone camera to document wiring before disconnecting

Probable causes

Very likely Drain pump motor has failed
Likely Wiring harness or connector to the pump is loose or corroded
Possible Control board isn't sending power to the pump circuit
Possible Drain solenoid has failed (models that use one instead of a dedicated pump motor)
Possible Impeller inside the pump is jammed by a hidden object
Rare Float switch stuck, preventing the fill/drain logic from progressing

First checks

Confirm — again — that the filter, drain hose, air gap, and (for new installs) the disposal knockout plug are genuinely clear; this page assumes they are.
Unplug the dishwasher and locate the drain pump, usually accessible from underneath the unit or behind the lower kickplate.
Visually inspect the wiring connector at the pump for corrosion, looseness, or a melted or discolored plug.
Check the float switch — a small cylinder that rises with the water level — for smooth up-and-down movement; it shouldn't stick.

Step-by-step diagnosis

With the dishwasher unplugged, disconnect the wiring connector at the pump and test the pump itself for continuity with a multimeter set to resistance.
A healthy pump motor typically reads around 130 to 150 ohms, though the exact spec varies by model — check your model's service documentation if available.
A reading of zero ohms or infinite resistance both indicate a failed pump that needs replacing.
If the pump tests within range, check for continuity from the control board's drain output to the pump connector — no continuity there points to a board or wiring fault rather than the pump.
If you can access the pump, spin its impeller by hand; grinding, resistance, or a wobble on an otherwise electrically healthy pump usually means a jam or a worn bearing.

Mistakes to avoid

Replacing the drain pump before testing it — control board or wiring faults are commonly mistaken for a dead pump.
Forcing a jammed impeller; removing the pump to clear the obstruction properly is safer than snapping a blade.

When to stop

If testing points to the control board, this is a good stopping point for most people — boards involve mains wiring and are usually cheaper to have diagnosed by a technician than to guess-and-replace.
Any scorched or melted connector at the pump or board: stop and call a professional rather than reconnecting power.

Parts potentially involved

Professional recommended for this problem

When to call a professional

If the simple checks didn’t solve it, if the fix involves electrical wiring, gas, or the refrigerant circuit, or if you have any doubt at all: stop there and hand the appliance to a qualified repair professional.

Related guides

Error codes for this appliance

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

July 20, 2026

Sam Radford — DiagnosFix

Technical reviewer

Last verified: 2026-07-17