Many homes are reliant on their trusty dishwasher so when issues arise, it’s a shock to the system to go back to washing dishes by hand. Naturally, if your dishwasher is not draining, you want to get it sorted as quickly as possible.

In this guide, we explain what to do when your dishwasher won’t drain. Before you shell out hundreds on a new one, or book in a repair, take a look at the things to check below – you never know, you may be able to rectify the problem with your blocked dishwasher yourself.

Before you get started, turn your dishwasher off at the mains.

How to Drain a Dishwasher with Standing Water

If your blocked dishwasher has left you with standing water, here are some tips for getting rid of it. You should do this before you start trying to diagnose the issue with the steps outlined later in this guide.

Using Vinegar and Baking Soda

Mix together a cup of baking soda and white vinegar and pour it into the standing water in your dishwasher. Leave it for around 20 minutes. If the water starts to drain, rinse with hot water and run the rinse cycle.

If the mixture has started to break down the blockage, the rinse cycle may be enough to dislodge it completely.

The Manual Method

If the above doesn’t work, you’ll have to clear the standing water in your dishwasher manually. Scoop the water out of the dishwasher with a cup or jug. When the water levels are low, absorb the remaining water with towels or cloths.

Diagnosing Why Your Dishwasher Won’t Drain: A Step-By-Step Guide

1. Check and Clean the Filters

Your dishwasher has filters which are designed to trap food and grease, preventing them from spreading through the machine. It goes without saying that these should be cleaned regularly, so if you are experiencing issues with your dishwasher not draining, it could be because your filters are blocked.

Usually, filters are found at the bottom of the dishwasher and normally twist off and lift out. Your dishwasher manual will provide further information about how to remove the filters on your specific model.

Once you’ve removed the cylindrical filter, you can then remove the metal mesh plate which will give you a better view of the sump. You may be able to see any blockages in the sump, such as large pieces of food, which you can remove.

To clean the filters, run them under hot water or use hot soapy water on more stubborn build-ups.

2. Check the Waste Hose

An important part of your dishwasher is the waste hose, which removes the dirty waste water from the machine. If after cleaning the filters, you still have a blocked dishwasher, check the waste hose for blockages.

You may find that the waste pipe is kinked, which is restricting water flow, or there may be a build up of grime inside the pipe. To check the pipe, you’ll need to pull out the dishwasher, which is easier to do with free-standing models.

3. Check Your Sink Isn’t Blocked

The waste hose of your dishwasher will usually drain into your sink waste pipe. If there is a blockage in your sink pipe, it could cause other issues, such as a dishwasher that won’t drain.

You can usually tell if you have a blocked sink as it will drain slowly or not at all. The good news is that there is often a simple fix to a blocked sink. For tips and advice, take a look at our guide on how to unblock a sink.

4. Check the Drain Pump

Your dishwasher has a drain pump which channels the water out of the machine after a cycle. If broken glass or food debris makes its way into the pump, it can impact how effective it is at draining water from the dishwasher. If this is the case, your dishwasher may sound louder than usual.

To check the drain pump is fully operational, you’ll need to disconnect the inlet hose and remove the base plate to gain access to the bottom of the dishwasher. You’ll have to take a resistance reading too. This is a little more technical than the other checks we’ve outlined so at this point, so you may prefer to call in a technician for a professional repair instead.

Hopefully, the above tips will help get your dishwasher running as it should be again. However, if you do suspect your issues are part of a wider drainage problem, get in touch with our team and we will be happy to help.

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