Dishwasher Not Cleaning Properly? Causes and Repair Solutions

Are your dishes still dirty, greasy or covered with food after a complete wash cycle? A dishwasher that is not cleaning properly may have a simple loading or maintenance problem, but it can also indicate a defective spray system, circulation pump, water inlet valve or detergent dispenser.

Joseph Services provides professional dishwasher diagnosis and repair in Montreal, Laval and surrounding areas. We identify why your dishwasher is leaving dishes dirty and determine the appropriate repair.

Why Is My Dishwasher Not Cleaning the Dishes?

Dishwasher cleaning problems can result from restricted water circulation, insufficient water, incorrect detergent use or a defective component.

Clogged Dishwasher Filter

The dishwasher filter collects food particles and debris. When the filter becomes clogged, water may not circulate or drain properly. Dirty water can also be sprayed back onto the dishes.

Remove and clean the filter regularly according to the dishwasher manufacturer’s instructions.

Blocked Spray Arms

Small pieces of food, mineral deposits or broken glass can block the holes in the spray arms. This reduces water pressure and prevents water from reaching every section of the dishwasher.

The spray arms should also rotate freely without hitting dishes, utensils or cookware.

Dishwasher Loaded Incorrectly

Overloading the dishwasher can prevent water and detergent from reaching the dishes. Large plates, cutting boards and pots may also block the spray arms or detergent dispenser.

For better cleaning:

Avoid placing dishes too close together
Face dirty surfaces toward the centre
Keep tall items away from the spray arms
Do not block the detergent dispenser
Place heavily soiled cookware where water can reach it

Not Enough Water Entering the Dishwasher

If the dishwasher does not fill with enough water, the spray arms may not have sufficient pressure to clean the dishes.

Low water levels can be caused by:

A restricted or defective water inlet valve
A problem with the float or float switch
A kinked water supply hose
Low household water pressure
A partially closed supply valve

Defective Circulation Pump

The circulation pump pushes water through the spray arms during the wash cycle. If the pump is weak, blocked or defective, you may hear the dishwasher filling without hearing strong water movement inside.

A circulation pump problem generally requires professional diagnosis.

Detergent Dispenser Not Opening

If the dispenser door remains closed, the detergent may not be released at the correct time. A large dish can physically block the dispenser, or the dispenser mechanism may be damaged.

After the cycle, check whether detergent remains inside the dispenser or at the bottom of the dishwasher.

Wrong Detergent or Insufficient Detergent

Using old, low-quality or insufficient detergent can reduce cleaning performance. Hard water may also require a different detergent amount or the use of a rinse aid.

Only use detergent specifically designed for automatic dishwashers. Never use regular liquid dish soap.

Water Is Not Hot Enough

Dishwashers need sufficiently hot water to dissolve detergent and remove grease. If the incoming water is too cold, dishes may remain greasy or stained.

Before starting the dishwasher, you can briefly run the kitchen faucet until the water becomes hot. If the dishwasher continues washing with cold water, its cycle, temperature sensor or heating system may need to be checked.

Wash Cycle Is Too Light

Quick, express and eco cycles may not clean heavily soiled dishes as effectively as a normal or heavy cycle. Choose a cycle that matches the amount of food and grease on the dishes.

Drainage Problem

If dirty water remains inside the dishwasher, it can contaminate the rinse water and leave residue on dishes.

A drainage problem may involve:

A clogged filter
A blocked drain hose
A defective drain pump
An incorrect drain hose installation
A blockage in the sink plumbing

Hard-Water or Mineral Buildup

White film or cloudy marks may be caused by hard-water minerals rather than food residue. Mineral deposits can also clog the spray arms and reduce cleaning performance over time.

Defective Sensor or Control Component

Modern dishwashers may use sensors to measure water temperature, cleanliness or water level. A defective sensor, wiring problem or control-board failure can affect cycle duration and cleaning performance.

What Type of Residue Is Left on Your Dishes?

The appearance of the dishes can provide clues about the problem.

Food Remains on the Dishes

Food particles may indicate clogged spray arms, a dirty filter, incorrect loading or weak water circulation.

Dishes Feel Greasy

Greasy dishes may result from cold water, insufficient detergent, a short wash cycle or inadequate water circulation.

White Film or Cloudy Glasses

White residue is commonly associated with hard water, excessive detergent or insufficient rinsing. Permanent cloudiness may be caused by glass etching.

Detergent Remains in the Dispenser

A blocked dispenser, defective dispenser mechanism, low water temperature or poor water circulation can leave detergent undissolved.

Upper Rack Is Not Cleaning

If only the upper rack remains dirty, check the upper spray arm and the water connection supplying it. Incorrect rack positioning or a blocked spray arm can prevent proper washing.

Lower Rack Is Not Cleaning

Poor cleaning on the lower rack may indicate a blocked lower spray arm, a circulation problem or large items obstructing the water flow.

What Can You Check Before Scheduling a Repair?

Before requesting service, you can safely:

Clean the dishwasher filter.
Check the spray-arm holes for visible blockages.
Confirm that both spray arms rotate freely.
Rearrange dishes so they do not block water flow.
Make sure the detergent dispenser can open.
Use fresh dishwasher detergent and the appropriate wash cycle.
Run hot water at the kitchen faucet before starting the dishwasher.
Check whether water remains in the tub after the cycle.

Disconnect the dishwasher’s electrical power before removing or inspecting internal parts. Do not attempt to test electrical components, pumps or wiring unless you have the proper training and equipment.

When Does a Dishwasher Need Professional Repair?

Schedule a dishwasher diagnosis when:

The dishwasher fills but you cannot hear water circulating
One or both spray arms are not receiving water
The detergent dispenser does not open
The dishwasher is not filling with enough water
The water remains cold throughout the cycle
Dirty water remains in the tub
Cleaning performance suddenly becomes worse
The dishwasher displays an error code
Cleaning the filter and spray arms does not solve the problem

Professional Dishwasher Diagnosis

A technician may inspect:

Dishwasher filter and drainage system
Upper and lower spray arms
Water inlet valve
Float and water-level system
Circulation pump
Drain pump and drain hose
Detergent dispenser
Temperature sensors and heating system
Wiring and electronic controls

Once the cause is identified, Joseph Services explains the problem and provides the repair cost before proceeding.

Dishwasher Repair in Montreal, Laval and South Shore

Joseph Services repairs dishwashers that are not cleaning properly in Montreal, Laval and surrounding communities. We diagnose many common dishwasher brands and cleaning-performance problems.

Do not continue rewashing the same load and wasting water, electricity and detergent. A proper diagnosis can determine whether your dishwasher needs maintenance, adjustment or replacement of a defective component.

Contact Joseph Services to schedule a dishwasher diagnosis and repair.

Call: 514-608-0650

Frequently Asked Questions

Why is my dishwasher running but not cleaning?

The dishwasher may be filling without circulating water properly. Possible causes include blocked spray arms, a clogged filter, insufficient water or a defective circulation pump.

Why are my dishes still greasy after washing?

The incoming water may not be hot enough, the selected cycle may be too short or the dishwasher may not be circulating enough water. Detergent type and loading can also affect grease removal.

Why does my dishwasher clean the bottom rack but not the top?

The upper spray arm may be blocked, unable to rotate or not properly connected to its water supply. Incorrect rack positioning can also interrupt the connection.

Why is the dishwasher tablet not dissolving?

The dispenser may be blocked by a dish, the water may be too cold or the dishwasher may have inadequate water circulation. A defective dispenser can also prevent the tablet from being released.

How often should I clean the dishwasher filter?

The appropriate frequency depends on how often the dishwasher is used and how much food remains on the dishes. Check the manufacturer’s instructions and clean the filter whenever visible debris accumulates.

Is a dishwasher that does not clean worth repairing?

It depends on the dishwasher’s age, overall condition, the cause of the problem and the availability of replacement parts. A professional diagnosis can help you compare the repair cost with replacement.

Every repair is covered by our 90-day warranty on parts and labour. See our warranty policy.