Dishwasher Not Cleaning Properly in Lewes - What to Check

Published August 2026 | Dishwasher Not Cleaning Properly What to Check

This checklist covers the most common reasons a dishwasher stops cleaning properly and what you can inspect, clean, or adjust yourself before calling in an engineer. Catching small problems early - a clogged filter, a worn spray arm, or low salt levels - typically saves you considerably more than the cost of a service call down the line.

Quick visual checks anyone can do

These are the first things our engineers look at when a customer in Lewes calls to report poor wash results. Most take under five minutes and need no tools at all.

1. Check the filter first. Pull out the lower basket and unscrew the cylindrical filter sitting in the base of the machine. If it's coated in grease and food debris, that's almost certainly your problem. A blocked filter restricts water flow and means dirty water recirculates over your dishes instead of draining away. Bosch and Siemens machines have a two-part filter system - a flat mesh plate and a cylindrical inner filter - and you need to clean both. Don't just rinse the outer part and reassemble.
2. Inspect the spray arms. The upper and lower spray arms have small jets that push water across your dishes throughout the cycle. Remove each arm - they usually unclip or unscrew anticlockwise - and hold them up to a light source. Any holes blocked with limescale or trapped food create dead zones in the wash. This is especially common in Hotpoint and Beko machines used in areas with harder water.
3. Check that spray arms rotate freely. Before closing the door, give each spray arm a spin by hand. If a tall pan or an awkwardly loaded item is catching the arm and stopping it mid-rotation, large sections of the load won't get proper water coverage. This is one of the most common causes of inconsistent cleaning results.
4. Look at the detergent dispenser. After a cycle, open the dispenser drawer and check whether the compartment is empty. If detergent is still sitting in there, the door didn't open at the right moment in the cycle. This is sometimes caused by an item blocking the drawer, but it can also be a failing latch mechanism. LG and Samsung dishwashers can develop build-up around the dispenser hinge that stops it springing open cleanly.
5. Examine the door seal. Run your finger around the rubber gasket lining the inside of the door. Hard patches, tears, or heavy mould build-up in the folds of the seal all affect performance. A poor seal lets heat escape during the wash, dropping the internal temperature and reducing cleaning effectiveness.
6. Check whether the machine is actually getting hot. During a 65-degree cycle, the door and sides of the machine should feel warm to the touch. If they're cool or lukewarm, the heating element may be failing. This needs professional diagnosis but it's worth ruling out before assuming the fault is elsewhere.

Monthly maintenance tasks

Running these checks once a month keeps most machines performing reliably and avoids the gradual decline in wash quality that catches a lot of homeowners off guard.

Clean the filter properly. Remove it, rinse it under a running tap, and use an old toothbrush to scrub away any stubborn grease or food residue. If the filter smells, soak it in warm soapy water for ten minutes before scrubbing. This one task prevents the majority of cleaning complaints our engineers see across East Sussex. It takes about three minutes and makes a significant difference.

Run a maintenance wash. Once a month, run an empty cycle on your machine's hottest programme using a dedicated dishwasher cleaner - Finish, Dettol, and Dr. Beckmann all make reliable products. This dissolves grease and limescale from internal components, hoses, and the pump chamber that you simply can't access by hand. Don't use washing-up liquid as a substitute - it creates foam that can damage the pump and seals.

Check your salt and rinse aid levels. Dishwasher salt softens incoming water and protects the internal components from limescale damage. East Sussex water hardness varies by location, but many properties around Lewes and the surrounding villages are supplied with moderately hard water, which means salt consumption is meaningful. Most machines have a salt indicator light, but it's worth manually checking the reservoir monthly rather than waiting for the warning. Low rinse aid causes water to bead on dishes and glassware rather than sheeting off cleanly, leaving spots and a dull finish.

Wipe the door seal and edges. Grease, mould, and food residue accumulate in the folds of the rubber gasket. A damp cloth with a small amount of washing-up liquid works well. If mould has taken hold, a solution of one part white vinegar to one part water will help shift it without damaging the rubber.

Annual professional checks you should book

Some components need a trained engineer and proper diagnostic equipment. Our engineers use the Voltrade GoFIX tool to run a full diagnostic across a machine's control board, temperature sensors, and electrical components - catching faults before they develop into complete failures.

Water inlet valve inspection. This valve controls how much water enters the machine at the start of each cycle. If it's partially blocked or the solenoid is starting to fail, the machine won't fill to the correct level and wash performance drops noticeably. Replacing an inlet valve typically costs between 80 and 150 pounds including labour, depending on the machine.

Heating element test. A failing heating element is one of the most common causes of cold, unsatisfying washes. An engineer can test it with a multimeter in minutes. Replacement parts for mainstream brands like Bosch and Hotpoint are usually available within a day or two. Full repair costs commonly fall between 100 and 185 pounds.

Pump and circulation motor check. The circulation pump forces water at pressure through the spray arms. As the pump wears, water pressure drops gradually - often so gradually that homeowners don't notice until cleaning quality has deteriorated significantly. Unusual noise during the wash cycle is commonly an early indicator of pump wear.

Control board and sensor diagnostics. Modern dishwashers from Samsung and LG in particular rely on sensors to manage water temperature, turbidity, and cycle timing. If a sensor is reading incorrectly, the machine may run shorter cycles or use cooler water than programmed. This is difficult to diagnose without proper equipment.

Most reputable appliance engineers in and around Lewes offer annual service visits. These typically cost between 65 and 120 pounds and cover a full inspection of all key components.

Warning signs that need immediate attention

These symptoms typically mean something is actively failing and running more cycles will make the situation worse.

• Standing water after a cycle ends. This points to a blocked or failing drain pump. Don't run another cycle - forcing more water through a struggling pump can cause further damage. Check the drain hose isn't kinked first, then call an engineer.
• Error codes on the display. Dishwashers from Bosch, Samsung, and LG show specific fault codes when something is wrong. Note the code down before clearing it - these codes save significant diagnostic time and are your machine's way of telling you exactly what's failing.
• Grinding or loud humming during the wash. A grinding sound usually means something is lodged in the pump impeller - a broken glass shard, a piece of bone, or a small utensil. A continuous hum with no water movement typically indicates pump failure.
• A burning smell at any point. Turn the machine off at the wall immediately. This indicates an electrical fault and the machine should not be used again until an engineer has inspected it.
• Water leaking from the door or base. Even a slow leak can damage kitchen cabinetry and flooring quickly. Check the door seal as a first step, but any leak that isn't immediately explained by an obviously damaged seal needs professional investigation.

If you're in Lewes or the surrounding areas of East Sussex and you're seeing any of these symptoms, it's worth getting a diagnostic booked promptly rather than waiting to see whether the problem resolves itself.

Your maintenance schedule

A simple calendar-based approach works better than trying to hold everything in your head at once.

Every wash:

• Load dishes with space between each item and check nothing blocks spray arm rotation
• Use the correct amount of detergent for your water hardness setting
• Scrape large food debris off plates before loading (you don't need to rinse them)

Monthly:

• Remove and clean the filter thoroughly
• Run an empty maintenance wash on the hottest programme
• Check and top up salt and rinse aid
• Wipe down the door seal and edges

Every six months:

• Remove spray arms and soak them in warm water to clear any blocked jets
• Check the door seal for cracking, hardening, or mould that won't wipe away
• Clean around the detergent dispenser hinge and check it springs open freely

Annually:

• Book a professional service, particularly for machines more than four years old
• Have the heating element, pump, and inlet valve tested
• Run a GoFIX diagnostic if the machine has been showing intermittent faults

Checklist questions

Why is my dishwasher leaving white residue on glasses and dishes?

White residue is almost always caused by limescale, low rinse aid, or a combination of both. In areas with moderately hard water - which applies to many properties around Lewes and across parts of East Sussex - limescale builds up on glassware and internal components over time. Start by topping up your rinse aid and confirming your salt level is adequate. If the problem persists after that, run a dedicated descaling cycle. You may also need to increase the machine's hardness setting, which controls how much salt the softener uses per cycle. Check your manual for instructions on adjusting this - it's usually in the settings menu on modern machines.

How often should I clean my dishwasher filter?

Our engineers typically recommend cleaning the filter every two to four weeks, depending on how often you run the machine and what you're washing. Families cooking from scratch daily and running the dishwasher once or twice a day will need to clean it more frequently than households using it three or four times a week. If dishes are coming out with small food particles stuck to them, or if there's a sour smell coming from the machine, those are reliable signs the filter needs attention sooner. It's one of those tasks that's easy to forget but has a significant effect on wash quality when left too long.

When is it worth repairing a dishwasher rather than replacing it?

A practical rule of thumb is to compare the repair estimate against roughly half the cost of a comparable new machine. If you're looking at a repair bill of more than 200 pounds on a mid-range machine that's already seven or eight years old, it's worth getting a replacement quote at the same time. Machines under five years old from established brands like Bosch, Hotpoint, or Beko are typically worth repairing - parts are available, and the machine has plenty of life left. Beyond eight to ten years, spare parts become harder to source and more expensive, and the overall reliability of the machine tends to decline regardless of what's repaired.