How to Unblock a Dishwasher
If you’ve noticed that your dishwasher isn't draining or has a bad smell, this can be a sign of a blockage in your dishwasher or further down the drain pipe.
It is best to clear a blockage as soon as possible, as it may take more work to do so later.
Following the steps in this guide can help you clear any blockages.
If you're still unsure whether you have a blocked dishwasher drain, our article ‘Signs of a blocked drain’ can help you identify the warning signs.
Why do dishwashers become blocked?
The leading causes of dishwasher blockages are large chunks of leftover food lodged in the drain.
Most dishwashers have a filter to catch food debris that is too large to go down the drain. These chunks can cause issues that are more difficult to remedy if they travel further down the pipe.
However, food can pass through this filter and congeal on the other side, forming a blockage.
Additionally, small items of cutlery, such as teaspoons, may dislodge from the racks and fall into the filter, damaging it or causing a blockage themselves.
Like most kitchen appliances that dispense wastewater, your dishwasher probably uses the same waste pipe as your sink.
If your dishwasher and sink drain slowly, the blockage may be in the main drainage pipes beneath the sink.
In this case, you should attempt to clear the blockage through your sink instead, as this is much more accessible than your dishwasher drain.
Is your dishwasher not draining?
Signs of a blockage include slow drainage or standing water collecting at the bottom of the main compartment.
You might also notice a foul smell or gurgling noises coming from the drains, especially when using your dishwasher or other appliances. Find out why this occurs in our article ‘Why does my sink gurgle when the washing machine drains.
If you discover that your kitchen drain is blocked, attempt to clear the blockage as soon as possible to prevent flooding your kitchen.
It is not always difficult to clear a blocked dishwasher, but it can be messy.
Step-by-step guide to unblocking a dishwasher
Step 1: Dress appropriately
You might get wet, so you need to start by wearing suitable clothes. Old clothes or an old pair of overalls work well for tasks such as these.
Step 2: Unplug the electrics
Your safety is important, so don't forget to switch off the power and water supply at the mains to prevent an electric shock.
Step 3: Clear out standing water
If you have stagnant water inside your dishwasher, there are two ways you can clear it before you attempt to unblock the dishwasher filters.
Option 1: Scoop the water out with a cup or small container and pour it into a bucket.
Option 2: Call in the drainage professionals
If you choose option 1, remember to dispose of any solid debris in the bin to prevent blocking another drain.
Step 4: Locate the dishwasher filter
The filter looks like a plastic or metal cover with tiny holes that sits over the waste pipe.
If you're having trouble finding it, try pouring some water in the dishwasher and watching where it drains.
For a dishwasher with multiple drains, repeat the process until you find the blocked one.
Step 5: Clean the filter
Before you remove the dishwasher filter, pay attention to its position so you can put it back correctly after cleaning.
Once you have carefully removed the filter and disposed of any trapped food debris, you should clean the filter and its parts with hot, soapy water to scrub away the stubborn bits.
Once clean, return the filter to its original position.
Step 6: Test the drainage
Pour a small cup of boiling water into the dishwasher and watch how it drains.
Why a small cup of boiling water? If it is still blocked, a complete cycle could lead to flooding.
Pass: If the boiling water drains quickly, congratulations, you can run a complete cycle to confirm that it's clear.
Fail: If the small cup of boiling water doesn't run properly, it's time to call in the professionals, as the problem may be further down the drain.
The team at Lanes have a wealth of experience, and we can quickly diagnose and fix the causes of blocked dishwashers with our CCTV drain surveys.
How to maintain your dishwasher
Maintaining your dishwasher is an important way to keep it running smoothly for years to come.
By taking a few simple steps, you can ensure that your dishwasher runs efficiently and reliably and reduce the risk of blockages in the future.
One of the most important things is to check and clean the filters regularly, just as you would to clear a blockage.
Doing this every couple of weeks can help to keep food particles and other debris from clogging the system and affecting its performance.
You should also avoid putting food waste down your drain. Make sure to scrape your plates into the bin as effectively as you can and give them a quick rinse and wipe before putting them in the dishwasher.
It is also important to check for any signs of leaking or malfunctioning parts – such as worn gaskets, loose connections, or cracked hoses – that could be causing water to escape. If you notice any of these issues, have them examined by a drainage expert immediately.
Our guide on how to fix a leaking pipe also explains more about what you can do if you have a leak.
You should also remember to use the correct amount and type of dishwashing detergent for your machine. This will help to ensure that it works effectively and prevent any build-up or corrosion that can occur if you use too much detergent.
How to prevent blocking your dishwasher drain
Fat, oils and grease are the leading causes of blockages and can damage your drains over time.
Although oil and grease flow easily in their liquid form, they quickly cool and solidify when they come into contact with colder water inside your drainage system.
Prevent your dishwasher drain from blocking by properly disposing of fat, oil and grease.
Our article ‘How to dispose of cooking oil in the UK‘ explains the best way to dispose of FOG safely.
Need help unblocking a dishwasher?
At Lanes Drainage Services UK, we specialise in unblocking drains and advising people on maintaining them and avoiding the more serious consequences of blockages.
If your dishwasher regularly becomes blocked or has a blockage that you can not shift, you should speak to us.
Our technicians can identify the source of the problem, clear the blockage, and advise you on how to avoid further problems, helping you get the most out of your kitchen appliances.
Call our 24/7 helpline today on 0808 167 6209. Alternatively, fill out an online enquiry form, and we will return your call at a time that works for you.