Appliance Repair · Service

Dishwasher repair — it is a plumbing appliance

Standing water in the bottom is usually the drain path, the air gap, or a knockout plug nobody removed on install day. None of those are the dishwasher, and none of them should cost what a dishwasher repair costs.

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In short

What is dishwasher repair?

Think of a dishwasher as plumbing with a heater in it. The two complaints people bring are it will not drain and it will not clean, and they share almost nothing. Draining is the sump filter, the drain hose, the air gap, the disposal connection and the pump. Cleaning is spray arms, water temperature at the tap, loading and detergent. Diagnosing one while describing the other is how people end up paying for parts they did not need.

Triggers

Signs you need dishwasher repair

A few inches of dirty water sitting in the bottom of the tub at the end of every cycle
Water bubbling or spitting out of the little chrome cylinder on the sink deck during the drain
The machine was installed recently and has never drained properly since day one
Dishes come out gritty or with dried food welded on, particularly on the top rack
Glassware comes out cloudy or filmed, and it does not wipe off
Water on the floor in front of the door, or a damp cabinet base you only noticed when something warped

Seeing something not on this list? Browse appliance repair problems by symptom →

The job

How dishwasher repair actually works

Establishing whether the fault is inside the machine at all

The first thing to establish on a drainage complaint is where the water stops. The sump filter at the base of the tub, the drain hose behind the cabinet, the air gap on the sink deck, and the connection into the garbage disposal or the waste tee are all outside the pump. Any one of them can hold water in the tub while the machine itself is perfectly healthy.

Watch for: A drain pump quoted before the filter has been lifted out and looked at. On many machines that filter twists out by hand in seconds and is full of debris.
The knockout plug — the fault that only affects new installs

Where a dishwasher drains into a garbage disposal, the disposal ships with a solid plug moulded into the dishwasher inlet. It has to be knocked out during installation. When it is not, the dishwasher can never drain, from the very first cycle. This is a five-minute correction that gets misdiagnosed as a failed pump often enough to be worth checking before anything else on a recently installed machine.

Watch for: A brand-new dishwasher that has never drained properly. That is an installation defect, not an appliance fault, and it may be the installer's responsibility rather than yours.
The air gap, the high loop, and backflow

The drain hose has to rise above the flood level of the sink so waste water cannot siphon back into the tub — either through an air-gap fitting on the sink deck or a high loop secured under the counter. When the air gap clogs, water sprays out of it onto the counter. When there is no loop and no gap, sink water finds its way into the dishwasher.

Watch for: Water appearing in the tub when you run the sink or the disposal. That is backflow from a missing high loop, and no part inside the dishwasher will fix it.
Poor cleaning, which is a different machine problem entirely

If the machine drains fine but dishes come out dirty, the questions are whether the spray arms turn freely and their holes are clear, whether the filter is choked, whether tall items are blocking the upper arm, and how hot the water arriving at the machine actually is. Wash performance depends heavily on inlet temperature, so a long pipe run from the water heater matters more than most people expect.

Watch for: Cloudy glassware being treated as a fault. Hard-water film and etching are water-chemistry problems that respond to rinse aid and a softener, not to replacement parts.
Leaks, separated by where the water actually comes from

Where it leaks tells the technician what it is. Water at the base of the door usually means a perished or displaced door gasket, a warped door, or overfoaming from the wrong detergent. Water under the cabinet with the machine idle points at the supply connection or the inlet valve. Water only during the wash points at the sump seal, a hose clamp, or the pump housing.

Watch for: A slow leak found only after the cabinet floor or the flooring has swollen. Anything under the machine is worth pulling forward and looking at properly rather than mopping.

Money

What does dishwasher repair cost?

Clearing a filter, an air gap or a knockout plug is at the bottom of the scale and is sometimes not chargeable beyond the visit. Drain pumps, inlet valves and door gaskets are modest parts. Control boards and full pump assemblies are where the arithmetic turns. Ask if the diagnostic is credited when you approve the work.

See the full dishwasher repair cost guide — by material, size and region →

Straight answer

When dishwasher repair is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

The tub or the inner door liner is cracked. A split tub cannot be sealed reliably and it will leak into the cabinet base. This is a replacement, and delaying it damages the floor as well.
The main control board has failed on an entry-level machine. Boards are among the priciest parts in the appliance, and on a budget unit the quote is likely to sit uncomfortably close to a new machine you would be happy with.
Racks, tines and the cutlery basket have rusted through. Bare rack wire rusts and rust marks everything you wash. Rack replacement parts are surprisingly expensive, and rust also indicates the interior finish has been failing for a while.
The problem is the plumbing, not the appliance. If the fault is a blocked branch drain, a missing high loop, or a disposal that has never been drilled out, do not buy dishwasher parts. Fix the connection.
It is going out in a kitchen renovation this year. A machine you have already agreed to remove is not worth a parts bill. Hand-wash for the interim.
The cycle problem is really water temperature. If the water reaching the machine is not hot enough, every wash disappoints and no repair changes that. That is a water heater or a distance-to-tap conversation.

Straight answer

Can I do this myself?

Reasonable to DIY

Removing and rinsing the sump filter, which on most modern machines twists out without tools
Clearing the spray arm holes with a toothpick and checking both arms spin freely by hand
Popping the cap off the air gap on the sink deck and clearing the debris inside it
Checking that the drain hose is looped high under the counter and not crushed behind the cabinet
Confirming a newly installed machine draining to a disposal had its knockout plug removed

Call a licensed pro

Any leak you cannot see the source of, particularly one that has already reached the cabinet base or the flooring
Drain pump, circulation pump or sump seal replacement, which means pulling the machine out from under the counter and disconnecting water and power
Inlet valve or supply-line work — a fitting that fails behind a cabinet floods a kitchen quietly
Control board, door latch switch and heating element faults, where mains voltage sits inches from standing water
A branch drain that backs up into the sink as well. That is not the appliance — see plumbing services

Before you sign

What to check when hiring for dishwasher repair

Will you check the drain path before you quote a pump?

Filter, hose, air gap and disposal connection all sit ahead of the pump and cost nothing to inspect. It is the fastest way to avoid an unnecessary part.
The machine is newly installed — can you confirm the disposal knockout was removed?

If it was not, this is an installation defect and possibly a warranty or installer callback rather than a repair you should be paying for.
Does the diagnostic fee come off the repair price if I proceed?

A dishwasher fix is often a small job. Whether the call-out is absorbed materially changes what the visit is worth.
How hot is the water arriving at the machine, and did you measure it?

Poor cleaning is frequently a temperature problem. A technician who measures rather than guesses saves you buying parts that were never faulty.
Will you pull the machine out to inspect underneath, or work from the front only?

Supply-side leaks and hose clamp failures are invisible from the front, and a slow one damages the cabinet before it damages the machine.
If the drain hose has no high loop, will you correct that while you are here?

It is a minute of work and it prevents sink water siphoning back into the tub — a fault people otherwise chase for years.

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Local pros

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Related work

Often done at the same time

Garbage Disposal Repair

Where the drain line usually goes

Washer Repair

The other pump-driven appliance

Refrigerator Repair

Cooling and sealed-system faults

Appliance Installation

Air gaps, high loops and supply lines done right

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FAQ

Dishwasher Repair — questions people ask

Still have a question? Talk to our team →

There is standing water in the bottom of my dishwasher. Is the pump dead?

Usually not. Work outwards from the tub: the sump filter, the drain hose behind the cabinet, the air gap on the sink deck, and the connection into the garbage disposal or waste tee. Blockage at any of those holds water in the tub while the pump is perfectly fine. The pump is the last suspect on the list, not the first, and it is also the most expensive one.

My new dishwasher has never drained. What did the installer miss?

Where a dishwasher drains into a garbage disposal, the disposal ships with a solid moulded plug in its dishwasher inlet, and the installer has to knock it out. Skipping that step is one of the most common install errors, and the machine simply cannot empty. If your unit was recently fitted and has never once drained, have this checked before anyone opens the appliance.

The dishwasher drains but the dishes are still dirty. What now?

Different problem, different checks. Spin both spray arms by hand — they must turn freely and their jets must be clear. Make sure a tall item is not blocking the upper arm. Clean the filter. Then run the kitchen tap until it is genuinely hot before starting a cycle, because wash performance depends on inlet temperature and a long pipe run means the machine fills with lukewarm water.

Why does water spray out of the little chrome cylinder on my sink?

That is the air gap, and it is doing what it is meant to do — visibly failing rather than letting waste water back into your dishwasher. Spraying means the line downstream of it is restricted, usually by debris caught in the gap itself or in the hose running to the disposal. The cap lifts off and the insert comes out; clearing it is a five-minute job.

Are cloudy glasses a sign the dishwasher needs repairing?

Generally no. Cloudiness is either hard-water mineral film, which wipes off and responds to rinse aid or a softener, or permanent etching from soft water and excess detergent, which does not come off at all. Neither is a mechanical fault, and the wipe test tells you which you have in a minute.