Why Your Dishwasher Isn’t Cleaning Properly (and When to Replace It)
A dishwasher that stops cleaning well is almost never broken. In the great majority of cases it’s one of a handful of maintenance issues, and the most common one takes two minutes to fix with no tools.
Work through these in order. They’re ranked by how often they turn out to be the answer.
1. The filter is clogged (start here, always)
Modern dishwashers, all the quiet ones, use a removable filter instead of a food grinder. Debris collects in it, and when it’s full, dirty water recirculates over your dishes instead of draining away. That’s why things come out gritty, filmy, or with bits stuck to them.
This is the single most common cause of "my dishwasher stopped cleaning."
Fix it: pull the bottom rack, twist out the cylindrical filter at the base of the tub, rinse it under the tap with a soft brush, and twist it back in. Two minutes. Do it every month or two.
If you’ve never done this and the machine is a few years old, prepare yourself for what’s in there.
2. The spray arms are blocked
The spray arms have small holes that jet water at your dishes. Those holes clog with food particles and hard-water mineral scale, and Houston’s water is hard.
Check: spin each arm by hand, they should turn freely. If an arm is stuck or sluggish, something is jamming it, often a large dish overhanging the rack, or a stray utensil.
Fix it: most spray arms unclip or unscrew by hand. Take them out, poke each hole clear with a toothpick or a straightened paperclip, rinse, and reinstall.
3. You’re loading it wrong
A dishwasher cleans with water sprayed upward from below. Anything that blocks that spray leaves a shadow, and everything in the shadow stays dirty.
- Don’t nest bowls or overlap plates. Water can’t reach through them.
- Face soiled surfaces down and inward, toward the center where the spray comes from.
- Nothing tall in the middle of the bottom rack, it blocks the arm below the top rack.
- Don’t overload. The most common overcorrection when things aren’t getting clean is to run it more often, but people usually just cram in more.
- Check the top arm spins before you close the door, a tall glass or a cutting board often stops it dead.
Full walkthrough: are you loading your dishwasher correctly?
4. The water isn’t hot enough
Dishwasher detergent needs heat to work. Enzymes and surfactants activate at temperature, and grease simply doesn’t dissolve in lukewarm water.
Your dishwasher wants water arriving at around 120°F. Two things to check:
- Your water heater setting. 120°F is the standard recommendation. If it’s set lower, the dishwasher suffers.
- Run the kitchen tap hot before you start the cycle. If the dishwasher pulls the cold water sitting in the pipe, the first and most important fill is cold. Running the tap for 20 seconds first genuinely improves results.
5. The detergent is old, wrong, or in the wrong place
- Detergent goes stale. Powder and pods absorb moisture and lose potency, especially in Houston humidity. If a box or bag has been open under the sink for a year, replace it.
- Don’t put the pod in the bottom of the tub. It dissolves during the pre-rinse and gets drained away before the main wash. It goes in the closed dispenser, which opens at the right moment.
- Never use dish soap. Not even a drop. It foams enormously and floods your kitchen.
- Use rinse aid. Not optional on a modern condensation-drying machine, more below.
6. Hard water scale (a Houston problem)
Houston has hard water, and over time mineral scale builds up inside the machine, on the heating element, in the spray arm holes, and as a white film on your glassware.
The white cloudy film on glasses is usually mineral deposit, not detergent residue. Test it: soak a cloudy glass in white vinegar for a few minutes. If it clears, it’s hard-water scale.
Fix it: run an empty hot cycle with a cup of white vinegar in a bowl on the top rack, or use a dishwasher-cleaning tablet. Do this monthly. Rinse aid also helps significantly, and a water softener solves it at the source.
7. It’s not draining fully
If you find standing water in the bottom of the tub after a cycle, the machine has been washing your dishes in dirty water.
Check, in this order:
- The filter (again).
- The drain hose, for a kink behind the machine.
- Your garbage disposal. If it was recently installed, the knockout plug may still be in place, which blocks the dishwasher drain completely. This is a shockingly common problem after a disposal install.
- The air gap on the counter, if you have one. It clogs.
8. You’re pre-rinsing too much
Counterintuitive but real. Modern dishwashers have soil sensors that measure how dirty the water is and adjust the cycle accordingly. If you scrub every dish spotless first, the sensor reads clean water and runs a short, weak cycle, and then whatever was baked on doesn’t come off.
Enzyme detergents also need something to grab onto.
Do this instead: scrape off solids, don’t rinse. Let the machine do its job.
9. Dishes come out wet (this one isn’t a fault)
Most modern dishwashers use condensation drying: the hot stainless tub evaporates water off the dishes. It works well on glass and ceramic. It leaves plastic wet, because plastic doesn’t hold heat. That’s physics, not a defect.
The $6 fix: rinse aid. It breaks water’s surface tension so it sheets off instead of beading. On a condensation-drying machine, rinse aid isn’t an optional extra, it’s part of the design. Most "bad drying" complaints are simply an empty dispenser.
Also: crack the door open at the end of the cycle and let it steam out for 20 minutes before unloading. And unload the bottom rack first, otherwise water pooled on upturned cups on the top rack pours onto the clean dishes below.
The checklist, in order
| Check | Time | How often it’s the answer |
|---|---|---|
| Clean the filter | 2 min | Very often. Always start here |
| Clear the spray arm holes | 10 min | Often |
| Fix your loading | Free | Often |
| Run the tap hot first | 20 sec | Often, especially in winter |
| Add rinse aid | 1 min | Nearly always, for spotting and wet dishes |
| Fresh detergent, in the dispenser | 1 min | Sometimes |
| Vinegar or cleaner cycle | 1 cycle | Sometimes, for hard-water film |
| Check the drain and disposal plug | 15 min | Sometimes, if water stands |
| Stop pre-rinsing | Free | Sometimes |
Work down that list before you call anyone. The overwhelming majority of "my dishwasher is broken" calls are solved in the top three rows.
When it’s actually time to replace it
If you’ve done everything above and it still doesn’t clean, now you can start considering the machine itself.
| Symptom | Typical repair | Verdict |
|---|---|---|
| Not cleaning after all the above | Wash pump / motor, $250–$450 | Replace if 8+ years old |
| Water not heating | Heating element, $150–$300 | Repair if under 7 years |
| Leaking from the door | Gasket, $80–$180 | Repair. Usually cheap |
| Leaking from underneath | Pump seal or tub, varies | Replace. A cracked tub is terminal |
| Won’t drain after clearing everything | Drain pump, $150–$300 | Repair if under 8 years |
| Control panel dead / unresponsive | Control board, $250–$450 | Replace |
| Rust inside the tub | — | Replace. The tub is failing |
| It’s 10+ years old and needs any real repair | — | Replace |
A dishwasher lasts about 9 to 12 years. The 50% rule applies: if the repair costs more than half the price of a replacement, don’t do it. And on an older machine, drop that threshold, a $300 repair on a 10-year-old dishwasher buys you very little runway. Framework here: when to repair vs. replace an appliance.
One more consideration that pushes toward replacing: a dishwasher from the last few years cleans and dries genuinely better than one from 12 years ago, and uses a fraction of the water. If yours has a plastic tub, that alone explains a lot of the poor drying, and a stainless tub is a real upgrade. See how to choose the right dishwasher and, if noise bothers you, are quiet dishwashers worth the extra cost?
Frequently asked questions
Why is my dishwasher not cleaning my dishes?
Start with the filter. In modern dishwashers a clogged filter is by far the most common cause: dirty water recirculates over your dishes instead of draining. Twist it out, rinse it under the tap, and put it back. Then check that the spray arms spin freely and their holes aren’t clogged.
How often should I clean my dishwasher filter?
Every month or two for a typical household, more often if you don’t scrape plates. It takes about two minutes: pull the bottom rack, twist out the filter at the base of the tub, rinse it with a soft brush, twist it back in.
Why are my glasses cloudy after the dishwasher?
In hard-water areas like Houston it’s usually mineral scale rather than detergent residue. Soak a cloudy glass in white vinegar for a few minutes; if it clears, it’s scale. Use rinse aid, run a monthly vinegar or cleaner cycle, and consider a water softener.
Should I rinse dishes before putting them in the dishwasher?
Scrape, don’t rinse. Modern dishwashers have soil sensors that adjust the cycle based on how dirty the water is, so pre-rinsing everything spotless can make the machine run a shorter, weaker cycle. Enzyme detergents also need some soil to work on.
Why does my dishwasher leave dishes wet?
Most modern machines use condensation drying, where the hot stainless tub evaporates the water. It works on glass and ceramic but leaves plastic wet, because plastic doesn’t hold heat. Fill the rinse aid dispenser, crack the door at the end of the cycle, and unload the bottom rack first.
How long does a dishwasher last?
About 9 to 12 years. Past 10, most significant repairs stop making financial sense: if a repair costs more than half the price of a replacement, replace it. A cracked tub, rust inside the tub, or a dead control board on an older machine are all effectively terminal.
Why is there standing water in the bottom of my dishwasher?
It’s not draining. Check the filter first, then the drain hose for a kink, then your garbage disposal, if one was recently installed, the knockout plug may still be in place, which blocks the dishwasher drain entirely. Also check the counter air gap if you have one.
Come see the difference for yourself
Home Star Appliances has served Houston since 2018 with new, scratch-and-dent, and quality-tested used refrigerators, washers, dryers, stoves, dishwashers, and microwaves, plus delivery, installation, parts, and financing. Come look at the units in person and ask us anything.
Visit us: 10216 Almeda Genoa Rd, Houston, TX 77075
Call: (713) 568-6088
Hours: Monday–Saturday, 9:00 AM – 7:00 PM (Sunday by appointment)
Browse our current inventory or contact our team.
Related reading
- How to Choose the Right Dishwasher for Your Home
- Are Quiet Dishwashers Worth the Extra Cost?
- Are You Loading Your Dishwasher Correctly? Common Mistakes Homeowners Make
- Built-In vs. Portable Dishwashers Explained
- How to Measure Your Space for a New Dishwasher
- Houston Homeowners: When to Repair vs. Replace an Appliance
- The Real Cost of “Cheap” Appliances vs. Certified Used
- When Appliance Repair Costs More Than Replacement
- How Long Do Appliances Really Last? (By Type)