Introduction
Is your dishwasher not draining properly? Few household problems are as frustrating as opening your dishwasher after a cycle only to find a pool of dirty water sitting at the bottom. At Budget Drains Nottingham, we understand how disruptive this common issue can be to your daily routine. The good news is that most drainage issues can be resolved without professional help. This comprehensive guide will walk you through the most common causes of a dishwasher that won’t drain and provide practical solutions to get your appliance working efficiently again. From blocked filters to pump problems, we’ll cover everything you need to know about fixing a dishwasher that’s not draining completely, including checking the dishwasher’s drain and cleaning the dishwasher’s filter.
Common Signs Your Dishwasher Has Drainage Issues
Before diving into solutions, it’s important to recognise the warning signs of a dishwasher with drainage problems:
Standing water at the bottom after a cycle finishes
Unpleasant odours coming from your appliance
Dishes remaining wet or dirty even after a complete cycle
Unusual noises during the drain cycle
Water backing up into your kitchen sink when the dishwasher runs
If you’ve noticed any of these symptoms, your dishwasher is likely experiencing drainage issues that need attention.
7 Common Causes of Dishwasher Drainage Issues
1. Clogged Drain Filter
A blocked dishwasher’s filter is one of the most common reasons for a dishwasher not draining. The filter system in your dishwasher is designed to trap food particles and other debris, preventing them from entering the drain pump. Over time, these filters can become clogged.
Most modern dishwashers have a filter unit at the bottom of the appliance, consisting of two components: a coarse filter and a cylindrical filter. To clean this:
Remove the bottom basket from your dishwasher
Locate the filter unit at the base of your appliance
Remove the cylindrical filter by turning it counter-clockwise
Remove the coarse filter clockwise
Rinse both components under very hot water
Use a small brush to clean away stubborn debris gently
Check for broken glass or foreign objects that might be stuck
Regular cleaning of your dishwasher filters every 1-2 months can prevent many drainage problems before they start.
2. Blocked Drain Hose
The drain hose connects your dishwasher’s drain to the sink drain or waste pipe. Water cannot flow out properly if this hose becomes blocked or twisted. Additionally, it is essential to regularly check the dishwasher’s drain to avoid water backups and ensure proper drainage.
To check the drain hose:
Disconnect your appliance from the power supply
Pull the dishwasher forwards to access the back
Locate the drain hose (usually a corrugated plastic tube)
Check for visible kinks or bends and carefully straighten any you find
Disconnect the hose and check for blockages
Use a drain snake to clear any obstructions
Flush with very hot water to remove residual debris
Ensure the drain hose is positioned correctly – it should have a high loop or be connected to an air gap to prevent water from flowing back into the dishwasher.
3. Faulty Drain Pump
The drain pump forces water out of your dishwasher. If it’s damaged or malfunctioning, water won’t be adequately expelled.
Signs of a problematic dishwasher pump include:
Humming sounds during the drain cycle
No sound at all when it should be draining
Standing water that doesn’t reduce at all
To inspect the pump:
Disconnect the power supply
Remove the lower spray arm and filter system
Locate the pump cover (refer to your appliance manual for specific location)
Check for foreign objects that might be blocking the pump area
Carefully test if the pump’s impeller moves freely
A blocked pump may be cleanable, but you’ll likely need a replacement part or professional assistance if it is faulty.
4. Blocked Air Gap (If Applicable)
Some installations use an air gap, a small cylindrical fixture mounted on the sink that prevents wastewater from flowing back into the dishwasher.
If your kitchen has an air gap:
Remove its cover by carefully unscrewing or pulling it off
Check for food particles or other debris
Clean thoroughly with a small brush
Rinse with hot water
A clogged air gap can cause water to back into the dishwasher, even if all other components work correctly.
5. Garbage Disposal Connections
If your dishwasher drains through the same drain line as your garbage disposal, issues can affect your dishwasher’s drainage.
Key points to check:
Ensure the knockout plug was removed when the disposal was installed
Check if recent disposal installation or replacement was done correctly
Run your disposal to clear any obstructions before running the dishwasher
Check that food debris isn’t blocking the connection point
The connection between your dishwasher and garbage disposal is a familiar trouble spot often overlooked.
6. Drain Valve Issues
Some dishwashers use a drain valve rather than solely relying on a pump to control water flow. If this valve is stuck or damaged, drainage problems can occur.
To check the drain valve:
Locate the valve bracket (usually near the pump)
Ensure it moves freely
Look for signs of damage or corrosion
A malfunctioning valve often needs to be replaced, which might require professional assistance depending on your comfort with appliance repair.
7. Control Board or Timer Problems
Modern dishwashers rely on electronic components to control drain cycles. If these are faulty, your dishwasher won’t drain properly even if all mechanical parts function.
Signs of electronic issues include:
Inconsistent draining (sometimes works, sometimes doesn’t)
Drain cycle not activating at all
Other cycle functions are also acting erratically
These problems typically require diagnostic equipment to identify accurately.
DIY Solutions: How to Fix a Dishwasher Not Draining
Safety First
Before attempting any repairs:
Disconnect the dishwasher from the power supply
Wear protective gloves to prevent cuts or exposure to bacteria
Place towels around the base to catch any water spills
Essential Tools
Torch
Screwdriver set
Container to collect water
Towels
Small brush
Drain snake
Teaspoon (for removing water)
Step-by-Step Guide to Fixing Drainage Issues
Remove Standing Water
Clean the Filter System
Check the Drain Hose
Inspect the Drain Pump
Natural Cleaning Solution
Test the Drainage
Advanced Troubleshooting Steps
If you’ve tried the basic troubleshooting steps and your dishwasher still isn’t draining correctly, it’s time to move on to more advanced troubleshooting. Here are some steps you can take:
Check the Drain Hose:
Ensure the drain hose is not kinked or twisted, as this can prevent water from flowing correctly. A twisted drain hose can obstruct water flow, causing drainage issues.
Disconnect the drain hose from the dishwasher and the sink drain. Inspect it for any blockages or kinks.
Use a drain snake to clear any obstructions. Once clear, flush the hose with hot water to remove residual debris.
Reconnect the hose, ensuring it is correctly positioned without sharp bends.
Inspect the Dishwasher’s Drain Pump:
The drain pump pumps water out of the dishwasher. If it’s not working properly, the water may not drain properly.
Disconnect the dishwasher from the power supply. Remove the lower spray arm and the filter system to access the pump.
Check the pump for blockages or debris. Look for foreign objects, such as broken glass, that might be obstructing it.
Ensure the pump’s impeller moves freely. If it’s stuck or damaged, you may need to replace it.
Clean the Dishwasher’s Filters:
Dirty or clogged filters can prevent water from flowing correctly. Check the dishwasher’s filter system, which usually includes coarse and cylindrical filters.
Remove the filters and rinse them under very hot water. Use a small brush to clean away any stubborn debris.
Regularly cleaning your dishwasher filters can prevent many drainage problems.
Examine the Dishwasher’s Drain Line:
The drain line carries water from the dishwasher to the sink drain. Check the drain line for any blockages or kinks.
Disconnect the drain line and inspect it thoroughly. Use a drain snake to clear any obstructions.
Reconnect the drain line, ensuring it is correctly installed without sharp bends or kinks.
Check the Sink Drain:
If the sink drain is clogged, it can prevent water from draining properly from the dishwasher.
Run water through the sink drain to check for blockages. Then, use a plunger or a drain snake to clear any clogs.
Ensuring the sink drain is clear can help your dishwasher drain properly.
Repair Options
If you’ve tried troubleshooting and your dishwasher still isn’t draining correctly, it may be time to consider repair options. Here are some options to consider:
DIY Repair:
You can fix the issue yourself if you’re comfortable with DIY repairs. Many common problems, such as a blocked filter or a clogged drain hose, can be resolved with essential tools and patience.
You can purchase replacement parts online or at a local hardware store. Consult your dishwasher’s manual for the correct part numbers and installation instructions.
DIY repairs can save you money and give you a sense of accomplishment, but be sure to take all necessary safety precautions.
Professional Repair:
If you’re uncomfortable with DIY repairs or if the issue is more complex, it’s best to hire a professional to fix it.
A professional technician can diagnose the problem accurately and provide a solution. They have the tools and expertise to handle more complicated issues, such as a faulty drain pump or control board.
While professional repairs can be more expensive, they can save time and ensure the job is done correctly.
Replace the Dishwasher:
If the issue is severe or if the dishwasher is old, it may be more cost-effective to replace it altogether.
Consider purchasing a new dishwasher that is energy-efficient and has advanced features. Modern dishwashers are designed to be more efficient and save money on water and energy bills in the long run.
Replacing an old, malfunctioning dishwasher can improve your kitchen’s overall performance and convenience.
Following these advanced troubleshooting steps and considering your repair options, you can address even the most stubborn dishwasher drainage issues and ensure your appliance drains appropriately.
Preventative Maintenance to Avoid Future Drainage Problems
Regular maintenance can prevent most dishwasher drainage issues:
Clean filters monthly
Scrape plates thoroughly before loading
Run hot water in the sink before starting the dishwasher
Use a dishwasher cleaner every 1-2 months
Check and clean the spray arms regularly
Inspect the drain hose connections every 6 months
Proper loading techniques also help prevent drain blockages:
Avoid overcrowding dishes
Position items so they don’t trap food particles
Ensure nothing falls through the racks that could block the drain
When to Call a Professional
While many drainage issues can be resolved with DIY methods, some situations warrant professional help:
You’ve tried all the above solutions with no improvement
The dishwasher makes unusual noises during draining
You notice water leaking onto the floor
The control panel shows error codes
You’re uncomfortable working with electrical components or plumbing
At Budget Drains Nottingham, our specialists are equipped to handle complex dishwasher drainage problems. Our repair hotline offers troubleshooting advice, and you can use our online booking tool to schedule a service call.
FAQs About Dishwasher Drainage Problems
Why is there standing water in my dishwasher after a cycle? Standing water typically indicates a drainage issue, most commonly a blocked filter, clogged drain hose, or pump problem.
How often should I clean my dishwasher filter? For most households, monthly cleaning is sufficient. However, bi-weekly cleaning may be necessary if you run your dishwasher frequently or don’t rinse dishes beforehand.
Can hard water cause dishwasher drainage problems? Yes, hard water can leave mineral deposits that affect the drain pump and valve functions over time. Using a dishwasher cleaner designed for hard water can help prevent these issues.
Is it normal for some water to remain in the dishwasher? A small amount of clean water (less than a teaspoon) in the sump area is normal. However, any significant amount of standing water indicates a problem.
How do I know if my drain pump needs replacing? If your pump makes unusual noises, doesn’t seem to run during the drain cycle, or if water remains after checking all other possible causes, the pump may need replacement.
Why does my dishwasher drain into my sink when running? This typically indicates a problem with the air gap, a clogged sink drain, or improper drain hose installation. The drain hose should form a high loop to prevent backflow.
What’s the white residue at the bottom of my dishwasher? White residue is usually mineral deposits from hard water or undissolved detergent. While not directly related to drainage, excessive buildup can eventually affect drainage components.
How long should a dishwasher take to drain completely? Most dishwashers should drain all visible water within 1-2 minutes. If it takes longer, there may be a partial blockage.
Conclusion
A dishwasher not draining properly is a common household problem with several potential causes, from simple blocked filters to more complex pump issues. Following our step-by-step guide, most drainage issues can be resolved without professional help. Regular maintenance is key to preventing future problems and ensuring your dishwasher provides years of trouble-free service.
At Budget Drains Nottingham, we’re committed to helping our customers maintain properly functioning appliances. Whether you need guidance on DIY repairs or professional assistance with more complex issues, we’re here to ensure your dishwasher drains perfectly every time.
Need Help With Your Dishwasher?
If you’re still experiencing drainage issues after trying these solutions, our expert technicians at Budget Drains Nottingham are ready to help. We specialise in various plumbing and drainage problems, including dishwasher repairs.
Contact our repair hotline today at 0115 990 2882 for immediate assistance, or use our online booking tool to schedule a convenient appointment. We offer competitive rates, a 100% satisfaction guarantee, and emergency service availability throughout Nottingham and surrounding areas.
Don’t let a dishwasher that won’t drain disrupt your daily routine—contact Budget Drains Nottingham today!
Published: 10th March, 2025 | Updated: 10th March, 2025