When your dishwasher is not cleaning well, it’s often something you can fix yourself. If you’ve been pulling dishes out only to find them still covered with food particles or grease, you may be able to fix it without costly repair bills.
So, let’s talk about the most common causes of a dishwasher not cleaning, and some simple ways I’ve fixed these problems and spared myself a repair call.
Reasons For a Dishwasher Not Cleaning Properly
Many times, dishwashers stop cleaning properly because they’re getting old, which means they need more maintenance than a newer appliance. Cleaning dirty filters, checking water supply issues and other simple steps can get even older dishwashers cleaning well again.
1. Dirty or Clogged Dishwasher Filter
A dirty dishwasher filter is like a stuffy nose: if it’s clogged, it will not work well at all. So, not surprisingly, a clogged filter is one of the most common reasons for a dishwasher not cleaning properly.
Depending on the age of your dishwasher, it may have a self-cleaning filter or a removable one. Consult your owner’s manual to determine the specific filter type. Clean your filter every month or two to help your dishwasher work optimally.
How to clean your dishwasher filter:
- Locate the filter under the racks and remove it from the machine—you may have to twist it, so look for directional arrows.
- Soak it in hot, soapy water for a few minutes.
- Scrub it with an old toothbrush. Avoid stiff brushes or scrubbing pads, which could damage the filter.
- Rinse the filter under hot running water.
- Reinstall it, twisting in the opposite direction of the arrows.
2. Clogged Spray Arms
Your dishwasher’s spray arms work like shower heads: if they’re full of gunk, they will not get things clean. Dishwasher spray arms shoot water through tiny holes to wash your dishes.
Over time, these holes can get clogged by food debris or hard water buildup. When that happens, it reduces water pressure and you’ll find your dishwasher not cleaning dishes properly.
How to clean your dishwasher’s spray arms:
- Remove the upper and lower spray arms. Some unscrew while others snap off—check your owner’s manual.
- Scrub the spray arm with soapy water and an old toothbrush to clean it.
- Use a toothpick or piece of wire to dislodge any clogs in the holes.
- Rinse the spray arm thoroughly under hot water.
- Reattach the spray arms and test the machine.
3. Improper Dish Loading
The right way to load dishes is a topic of contention in many households. The fact is, loading dishes properly has a direct impact on how well your dishwasher can clean them.
The upright prongs or tines in your dishwasher rack are there to keep dishes from bumping into each other, not to act as hooks. When loading dishes, place them between, not on, the tines. Then, angle them downward so water from the spray arms can reach the soiled surface to get them clean.
4. Wrong Detergent Amount or Quality
With cleaning products, more is not always better. Using too much detergent or the wrong type can cause a build-up of residue on your dishes, making them appear dirty even after a wash cycle.
Not using rinse aid can also result in streaky or cloudy dishes and glassware, though it’s a tradeoff because rinse aid is linked to glasses that smell like a wet dog.
How to use dishwasher detergent correctly:
- Use only automatic dishwashing detergent, as other detergents or soaps can affect performance or cause suds to overflow.
- If you have hard water, look for a dishwasher detergent with water softeners built in.
- Use the right amount of detergent for your load size, usually one detergent pack or tablet per load.
- Do not block the dishwasher detergent dispenser with dishes.
- Add rinse aid to help minimize the buildup of hard water mineral deposits. In some machines, you may use vinegar in the rinse aid compartment—check your owner’s manual.
Where To Put Dishwasher Pods?
Do not throw dishwasher pods in the bottom of the machine. Dishwashers use a pre-rinse to remove the first layer of grime, then they release the dishwasher pod. Having the pod at the bottom means it dissolves in the pre-rinse then is drained away, so your dishwasher won’t get your dishes clean.
5. Inadequate Water Supply or Temperature
If your dishwasher is not cleaning dishes, it could be due to a problem with your water temperature or supply. It’s like trying to take a shower with low water pressure or cold water: you’ll get water, but not enough to rinse away the shampoo and conditioner.
How to prime your dishwasher:
- Check that the water supply is on fully. Many times, items in the cabinet beneath the kitchen sink knock the water supply valve and close it slightly.
- Make sure your home’s water heater is between 120°F and 140°F (49°C and 60°C), which is hot enough to remove grease from dishes but not hot enough to melt plastic or burn if you touch it.
- Run hot water in the sink closest to the dishwasher for at least 30 seconds before starting a wash cycle to ensure that hot water is running to your dishwasher.
6. Dirty Dishwasher Interior
Finally, a dirty dishwasher interior can also cause dishes to come out less than sparkling. Soils, detergent, mold, food residue, and minerals can build up and keep your dishwasher from cleaning well.
How to keep your dishwasher clean:
- Remove and wash the filter regularly, especially after greasy meals.
- Run a dishwasher cleaning tablet through the machine monthly to remove buildup.
- Leave the dishwasher door open slightly after use so the interior can fully dry to present mold.
- Once a month, clean your dishwasher, including the gasket and racks. This will extend the lifespan of your appliance and help your dishwasher clean your dishes well.
When to Call a Technician?
If you hear a hammering sound when your dishwasher runs, or your dishwasher’s not cleaning properly after performing the steps above, it may be time to replace the water inlet valve.
If you’re a confident DIYer, there are plenty of videos online to show how it’s done. Otherwise, contact a professional repair person to fix your appliance or let you know if it’s time for a new one.