How Do I Know If Dishwasher Drain Pump Is Bad?

Dishwashers rely on a drain pump to remove used water from the appliance. When the pump goes bad, the dishwasher should display an error code to let you know. But is that the only way you can tell if your dishwasher drain pump is bad?

There are several signs to look for that indicate your dishwasher drain pump is bad. For instance, a bad pump causes the appliance to drain too slowly or not drain at all. Besides that, you’ll find water leaking out onto the floor or left standing inside the compartment, even after a wash program ends. Lastly, low humming or squealing noises also point to a pump problem.

This guide will walk you through the telltale signs that your dishwasher drain pump is bad. When you’re able to identify these signs early, you can troubleshoot and repair the pump before it fails entirely, leaving you with dishes you can’t wash.

5 Signs Your Dishwasher Drain Pump Is Bad

Dishwashers will typically flash an error code to let you know that the drain pump is going bad. However, these appliances don’t always do that in a timely fashion. So instead, here are a few tell-tale signs you can look for that tell you the dishwasher drain pump is going bad.

#1 Doesn’t Drain At All

The first and most evident sign of a failed drain pump is that your dishwasher stops working during the drain cycle. Instead of driving water out of the compartment and into your household drainage system, the dishwasher will pause and not move on to the next stage.

Naturally, this is a significant problem because the appliance cannot remove greywater and continue washing your kitchenware. Plus, your dishes will get even dirtier if the machine continues washing them with used water.

Still, you must understand that this problem still requires some troubleshooting. That’s because a failure to drain isn’t always the fault of a failed drain pump. For example, a clogged drain could also prevent the dishwasher from draining.

So, you’ll have to inspect your drain pump to confirm that it’s the root cause of your dishwasher’s failure to drain.

Read: How To FIX Any Dishwasher When Its Not Draining

#2 Takes Too Long To Drain

The whole point of a drain pump is to help drive water out of the dishwasher quickly instead of relying on gravity to do all the work. So, a drain pump that’s in good working order should only take a few minutes to remove all water from your appliance.

Of course, the precise timing will be different depending on your dishwasher model, brand, and size. Larger dishwashers have more water for the pump to remove, and some models use stronger pumps than others.

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If you’ve had the appliance for a long time now, you’d have a strong sense of how fast the dishwasher should drain. Plus, you can refer to the user manual, which details how long the process should take.

Still, if you start to notice that your dishwasher is spending too much time in the drain stage of the wash cycle, that’s a sign that the drain pump isn’t working as efficiently as it should. You can preemptively have someone diagnose the pump for you instead of waiting for it to fail.

#3 Standing Water After Wash Program Has Ended

You should find no leftover water inside the dishwasher compartment at the end of your chosen wash program. That’s because the final stage of any wash cycle is to remove all remaining water and push it out through the drain hose.

However, a dishwasher with a problematic drain pump will leave standing water inside the appliance even when it shouldn’t. So, if you see that there’s a puddle in your dishwasher, you should inspect the drain pump and its electrical connectors.

If there are no clogs and the drain pump is connected as it should be, then you’ll likely have to replace it with a new one.

Read: Dishwasher’s Door Latch Stuck Closed – How To Fix It

#4 Low Humming Noise

Besides how well the appliance drains the water, you can also look out for telltale signs in the form of sounds. 

For example, a low and continuous humming noise coming from your dishwasher is another sign of trouble. The sound occurs because the drain pump has a foreign object stuck inside it.

Foreign objects are a significant problem for dishwasher drain pumps because of how they function. 

Remember: the drain pump consists of a motor and an impeller that drives water out through the drain hose.

So, when a foreign object finds its way through the dishwasher and into the pump, it will prevent the impeller from turning. As a result, the drain pump tries and fails to do its job.

This sign of a bad drain pump often comes with accompanying symptoms. Those symptoms are the ones that we’ve seen at the beginning of this list, which are:

  • Slow or delayed draining of water from the dishwasher.
  • No draining of water from the dishwasher at all.
  • Leftover standing water inside the appliance after the wash program ends.

You can fix this problem by removing the foreign object causing the humming noise and preventing the impeller from turning. However, that’s not always possible. If necessary, replace the drain pump with a new one.

#5 Squealing Noise

Another sound to look out for is a loud and loud squealing noise coming from inside the dishwasher. This problem is more likely to happen with dishwashers that you’ve been using for many years, and it’s a sign of worn-out bearings.

Like many other appliance components, your dishwasher drain pump relies on bearings so the impeller can turn smoothly, even at high speeds. So, your drain pump can’t work correctly when its bearings aren’t in good shape.

When the bearings become faulty or worn out, the impeller will struggle to turn. But more importantly, it’ll also generate the squealing noise you’re hearing.

Depending on your dishwasher brand and model, you might be able to replace the worn-out bearing by itself. If not, you’d be better off replacing the pump entirely, especially if it’s an old pump. The older the part, the more likely it is to face other problems later.

Read: Are All Dishwashers Hardwired?

#6 Water Leaking Onto Floor

Last but not least, a lousy dishwasher drain pump can also lead to water leaking onto the floor. That’s because water collects inside the dishwasher compartment, but the pump fails to drive it out through the drain hose.

So, as more and more water accumulates inside the dishwasher, some of it will flow out through openings that lead it to your kitchen floor.

The solution to this problem depends on what’s causing the pump to fail. Like with #5, there are some pump components you can replace. For those that you can’t, you’ll have to replace the pump unit with a new one.

Read: Use Of Salt In A Dishwasher

Frequently Asked Questions (FAQs)

Here are some other questions you might have regarding bad dishwasher drain pumps:

How Much Does It Cost To Replace A Dishwasher Drain Pump?

If you have to replace your dishwasher drain pump, you can expect to pay an average of $150 to $350. The exact price you’ll pay depends on your dishwasher’s brand and model. The pumps for some high-end models can cost as much as $600.

Can A Dishwasher Pump Get Clogged?

Yes, a dishwasher drain pump can suffer from clogs. That will happen when too many food bits and foreign objects make their way past the filter and find their way directly into the drain pump. When those objects fail to pass through the pump, they’ll instead cause a clog and prevent the pump from working.

Why Do Dishwasher Drain Pumps Fail?

Dishwasher pumps can fail mechanically and electrically. Mechanically, foreign objects and food bits can jam the pump’s impeller and prevent it from turning. Electrically, the pump could suffer from faults like short circuits and power surges that damage it from the inside.

How Long Do Dishwasher Pumps Last?

Dishwashers and their parts (including the drain pump) can last an average of 10 years. However, you can lengthen that lifespan by ensuring that your dishwasher is well-maintained and cleaned.

Read: Should You Use Dishwasher Detergent Substitute’s?

What Does A Bad Dishwasher Drain Pump Sound Like?

A bad dishwasher drain pump will create a low humming noise if its impeller fails to turn or a loud squealing noise if its bearings are worn-out. But, of course, a drain pump that fails ultimately will not make any noise, even when it should be running.

Read: Are Dishwashers More Efficient And By How Much?

Reader Comments (1)

  1. How can i check electrically the drain pump of Bosch dishwasher.There are three
    contacts on the board and the resistance between them is 90 kohm Its o.k.?


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