Dishwasher Not Draining? How to Fix It (or Know When to Call a Repair Tech)

Quick answer: Standing water in the bottom of a dishwasher after a cycle is almost always one of three things — a clogged filter basket, a kinked or blocked drain hose, or (if you’ve recently had a garbage disposal or new sink fitted) a knockout plug that was never removed from the drain line. All three are checkable in a few minutes without tools. If the pump is humming loudly but nothing drains, that’s a motor fault and needs a technician.

1. Clean out the filter basket

Almost every dishwasher has a removable filter assembly at the bottom of the tub, usually a twist-lock cylinder in one corner. Food scraps, labels and broken glass build up here over time and are the single most common cause of poor draining. Twist it out, rinse it thoroughly under the tap, and clear any debris from the recess it sits in before replacing it.

2. Check the drain hose for kinks or blockages

The corrugated drain hose runs from the back of the dishwasher to either the sink’s drain pipe or the garbage disposal. If the dishwasher’s been moved, or cabinetry work has been done nearby, the hose can end up kinked or pinched behind the unit. Pull the dishwasher out carefully and check the hose runs in a smooth loop with no tight bends.

3. Check the air gap or disposal knockout plug

If your dishwasher drains through an air gap fitting on the sink, check it isn’t clogged — unscrew the cap and clear any buildup. If it connects to a garbage disposal unit, and that disposal was installed or replaced recently, there’s a knockout plug inside the disposal’s inlet that has to be removed for the dishwasher to drain — it’s a very common miss during installation.

4. Don’t overdo the rinse aid or use the wrong detergent

Using dish soap instead of dishwasher detergent, or too much rinse aid, creates excess foam that can overwhelm the drain pump and leave water sitting in the tub. If you’ve noticed suds along with the standing water, that’s your answer — switch products and run an empty cycle to clear it.

When it’s a job for a technician

If you’ve cleared the filter, checked the hose and the air gap or disposal plug, and there’s still water sitting in the bottom — especially if you can hear the pump humming or straining without anything draining — the drain pump motor, a check valve, or the control board has likely failed. Standing water left in a dishwasher can also start to smell and encourage mould around the door seal, so it’s worth getting looked at sooner rather than later. Our dishwasher repair technicians in Hobart, Indiana diagnose most drainage faults on the first visit, with upfront pricing before any work begins.

Frequently Asked Questions

Why is there standing water in the bottom of my dishwasher?

Most often it’s a clogged filter basket or a kinked/blocked drain hose. If the dishwasher was recently connected to a new garbage disposal, check that the disposal’s knockout plug was removed — it’s a common installation miss that stops draining completely.

Can I run my dishwasher if it’s not draining properly?

We wouldn’t recommend it. Running a cycle on top of standing water won’t clean dishes properly, can make the smell and mould risk worse, and if the cause is a failing pump motor, continuing to run it can burn the motor out completely.

How much does dishwasher repair cost in Hobart, Indiana?

It depends on the cause — a hose or filter issue is generally inexpensive, while a drain pump motor replacement costs more. See our appliance repair cost guide for what typically affects the price, or we’ll diagnose and quote upfront before starting any work.

Still got water sitting in the tub after trying the above? Book a technician online — we repair dishwashers right across Hobart, Indiana. You might also find our guides on what to check if your dishwasher is leaking water or what to check if it isn’t cleaning dishes properly useful.

Want to avoid a repeat call-out? See our appliance maintenance checklist.