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5 Reasons Why Your Dishwasher Won’t Drain

25th December 2023

Are you tired of facing the frustrating ordeal of your dishwasher not draining properly? We’ve all been there – standing in front of the dishwasher, peering inside, only to find stagnant water at the bottom, not only leaving you with dirty dishes and lingering odours but also the worry of calling someone out to perform costly repairs, or if worse comes to worst, forking out expenses on a replacement dishwasher!

Fear not as the experts at Cotswold Drainage have the solutions for you. We’re ready to assist you in fixing any immediate drainage issues and in this blog, we’ll outline the reasons and solutions as to why your dishwasher won’t drain.

Common Signs That Your Dishwasher is Not Draining

The first act in addressing this dire problem is to recognise the signs. The first and most prominent sign of your dishwasher not draining is the presence of water pooling at the bottom of the dishwasher. The water may be producing foul odours and contain stubborn residue clinging to your once spotless dishes. If this problem is not fixed, then the user experience and cleanliness of your kitchen will be at high risk.

Why is My Dishwasher Not Draining? – The 5 Reasons

There are several reasons why your dishwasher won’t drain and understanding each reason will help you decide on the best solution.

1. Your Filters are Dirty

The first main cause of your dishwasher water not draining is all about your filters being too dirty or blocked. Regular cleaning of your dishwasher filter is essential to stop this problem from happening, with a recommended fortnightly cleaning.

Dishwasher filters trap food particles and stop them, as well as fats and grease, from re-entering your dishwasher, so giving them a good clean and seeing to regularly will help them function optimally.

2. Your Disposal Connection is Compromised

This reason is only for those who have their dishwasher connected to your kitchen’s waste disposal system. Problems with the connection can impede your dishwasher drainage. A quick way to check if this is the issue is to run your disposal for about 30 seconds which may help remove air gaps in the hose or properly dispose of trapped waste.

3. Dishwasher Pump Problems

The dishwasher pump is responsible for draining water from the appliance. If this has malfunctioned, it can lead to significant drainage problems. The drainage pump can malfunction due to various reasons, including broken glass and foreign objects slipping into the pump, or leftover food and grease preventing the water from being drained.

4. Clogged Drain Hose

Sometimes, the culprit behind why your dishwasher won’t drain is because of a clogged drain hose. The drain hose’s function is to carry dirty water away from the appliance and is typically connected to the same drain line as your kitchen sink. Your drain hose could be clogged with all types of contaminants, but unblocking can be quite simple by using a plunger or a drain snake.

5. Faulty Drain Valve

While not all dishwashers have drain valves, you should check yours (if you have one) for any issues. To see if the valve is working properly, push on the valve bracket, if it doesn’t move around and if the valve bracket is stuck, then you have a faulty one.

DIY Solutions for Restoring Dishwasher Drainage

Prevention is often the best cure, and we can’t emphasise enough how important it is to regularly clean and maintain your dishwasher to keep clogs and build-up at bay.

However, if you find yourself in the situation where your dishwater is not draining water, we have the DIY solutions to help you out.

First, disconnect your dishwasher from the mains and completely empty it of crockery, plates glasses and cutlery. It will also help to remove the two mesh holders so you can get full access to the parts that need fixing.

Clean your dishwasher’s interior, filters, valves and everywhere in between and continue to do so periodically to prevent debris buildup.

There are also some amazing natural remedies to unclog mild build-up. Mix together some vinegar and baking soda, place the mixture in a dishwasher-safe container on the top rack and run a cycle. The concoction of vinegar and baking soda will act as a great cleaner of dirt, grease, food and anything that is causing blockages.


A dishwasher that refuses to drain can be a frustrating problem, but it’s one that can be resolved with the right knowledge and regular cleaning and maintenance. Remember, proactive maintenance is key to preventing drainage issues, and while DIY solutions can help, it doesn’t hurt to seek professional assistance. Cotswold Drainage is here to help get your dishwasher back in working order, as well as help solve various drainage issues around your home. For help no matter the drainage issue, get in touch with us today and we’ll fix the problem.