A dishwasher that leaves water in the bottom or dirty plates in the rack is frustrating, and it is often an easy fix. This guide covers the common causes, the checks you can safely do yourself and the faults that need an engineer.
Switch the dishwasher off at the socket before you check inside it, and have towels ready for water.

If the dishwasher won't drain
- Clean the filter. Twist out the filter in the base of the tub, rinse it and clear any food or glass. This solves the majority of standing-water problems.
- Look for blocked food or objects in the sump below the filter.
- Check the drain hose behind the machine for kinks or squashing, and make sure it is connected correctly to the sink waste. If the sink waste is blocked, the water has nowhere to go.
- Run a short programme and listen. If the drain pump is silent or humming without moving water, it may have failed.
If the dishes aren't getting clean
- A blocked filter or spray arm. Clean the filter, then check the holes in the spray arms for food and limescale.
- Overloading or bad loading. Big items can block the spray arms or the detergent drawer. Don't stack dishes so that they nest together.
- The wrong detergent or too little of it. Use dishwasher detergent in the right amount, and check any salt and rinse aid are topped up.
- Hard water. Limescale leaves a white film and weakens the wash. A cleaning cycle with a descaler helps.
- Low water temperature or a faulty heater. If dishes aren't hot at the end and grease isn't shifting, the heating element or sensor may be failing.
If it smells
Clean the filter, wipe the door seal and run a hot cleaning cycle with a dishwasher cleaner. Our guide to dishwasher maintenance explains the routine.
Faults that need an engineer
- A failed drain pump or blocked internal hose
- A faulty inlet valve, so the machine doesn't fill properly
- A failed heating element or thermostat
- A door latch or seal fault that causes leaks or stops the cycle starting
- Error codes you can't clear
We repair dishwashers of all makes, including built-in and freestanding models, across Caerphilly and the surrounding valleys, from £70 + VAT with a 90-day guarantee. See our dishwasher repair page.
Call us on 029 2088 5355 for a quote, or book online. Same-day or next-day where possible, repairs from £70 + VAT, and a 90-day guarantee on every repair.
Book a repair onlineFrequently asked questions
Why is there standing water in the bottom of my dishwasher?
The usual causes are a blocked filter, a clogged drain hose or air gap, a kinked waste hose, or a failed drain pump. Clean the filter first, check the hose behind the machine and run a short drain programme.
Why are my dishes coming out dirty or gritty?
A blocked filter or spray arms, overloading, using too little detergent, or a low water supply. Clean the filter and spray arms and check the load before you suspect a fault.
Can I use washing-up liquid in a dishwasher?
No. Washing-up liquid creates too many suds and can cause leaks and poor cleaning. Use detergent made for dishwashers.
Is it worth repairing a dishwasher?
Often, yes. Pumps, filters, door seals and spray arms are routine repairs. Ask for a quote and compare it with the cost of a new dishwasher.




