Dishwasher Not Cleaning Properly in Weybridge - What to Check First

Published September 2026 | Dishwasher not cleaning properly what to check

This guide walks you through the most common reasons a dishwasher stops cleaning properly and shows you how to diagnose and fix the most likely causes yourself. It's aimed at homeowners in Weybridge and across Surrey who want to run through a few practical checks before calling out an engineer.

Before You Start - Safety First

Before you touch anything inside the machine, switch it off at the wall and make sure any current cycle has finished completely. Don't reach into the tub while the appliance is connected to power, and never attempt to access internal wiring, the heating element terminals, or the water inlet valve unless you're qualified to work on electrical appliances.

If your dishwasher has been leaking water onto the floor, producing a burning smell, or tripping the circuit breaker, stop using it immediately. Unplug it, and call an engineer rather than attempting further investigation yourself. The checks in this guide are low-risk and hands-on, but a machine showing signs of electrical or serious mechanical fault is a different matter entirely.

What You Will Need

For the checks and cleaning steps covered here, gather the following before you start:

• A soft-bristled brush or old toothbrush
• A cocktail stick, skewer, or thin piece of wire
• Household white vinegar
• A dishwasher cleaning tablet (Finish Power Up or similar)
• Dishwasher salt and rinse aid if you haven't topped these up recently
• A torch or phone light
• A clean cloth or sponge

Set aside around 45 to 60 minutes for the initial inspection and cleaning work. Some steps involve running a full cycle, so the total time from start to finish could be two to three hours, but most of the hands-on effort takes well under an hour.

Step-by-Step Instructions

Step 1 - Check and Clean the Filter

The filter is the single most common cause of poor cleaning results, and it's also the easiest thing to fix. Most dishwashers have a cylindrical filter assembly sitting at the bottom of the tub, usually beneath the lower spray arm. On Bosch and Hotpoint models you typically unscrew it by rotating it anti-clockwise; on Beko and Indesit machines it usually lifts straight out. Check your manual if you're not sure which mechanism yours uses.

Once removed, rinse the filter under hot running water and use your brush to scrub away any food debris, grease, or chalky residue. Weybridge sits in a hard water zone, and limescale build-up on the filter mesh is extremely common in this part of Surrey. If yours looks heavily scaled, soak it in a bowl of white vinegar for 15 minutes and then rinse thoroughly before refitting.

A clogged filter restricts water circulation, which means dirty water recirculates over your dishes rather than draining away cleanly. Our engineers find that in the majority of call-outs for poor cleaning results across the Weybridge area, a blocked or partially blocked filter is either the main cause or a significant contributing factor.

Step 2 - Inspect and Clear the Spray Arms

Your dishwasher has two or three spray arms - one beneath the lower basket, one beneath the upper basket, and sometimes a fixed one at the very top of the tub. These spin during the wash cycle and spray water through small jets. If those jets become blocked with food particles or limescale, water pressure drops noticeably and cleaning suffers across the whole load.

Remove each arm by unscrewing or unclipping it. Samsung and LG models use slightly different release mechanisms to older European brands, so it's worth a quick look at your manual if the arm doesn't come away easily. Once removed, hold each arm up to your torch and look through the jets. Use a skewer or thin wire to clear any blocked holes, rinse the arms under a hot tap, and refit them. Before you run the next cycle, check that each arm rotates freely by hand. If an arm is stiff or catches on a basket fitting, it won't spin properly during the wash.

Step 3 - Top Up Salt and Rinse Aid

Dishwasher salt softens the water inside the machine and prevents limescale from damaging the internal softener unit. Rinse aid helps water sheet off dishes and glassware during the drying phase. Both of these have a direct effect on cleaning and finishing quality.

The salt compartment is usually a screw-top cap set into the floor of the tub. The rinse aid compartment sits on the inside of the door, most commonly on the left-hand side. If either is empty or running low, top them up now. Always use salt designed specifically for dishwashers - not table salt or sea salt, which can damage the softener. Given that hard water affects much of Surrey, salt is particularly important in Weybridge homes. Many machines have indicator lights for both, but the sensors aren't always reliable, so check manually if you're not sure.

Step 4 - Check the Water Temperature

Dishwashers rely on hot water to dissolve detergent effectively and cut through grease. The main wash cycle typically runs at 55 to 65 degrees Celsius, with intensive programmes reaching 70 degrees or higher. If the machine isn't reaching these temperatures, detergent won't dissolve fully and grease won't lift from surfaces.

A quick check: run a cycle and place your hand flat on the door after around 20 minutes. It should be noticeably hot. If it only feels warm, this could point to a failing heating element or thermostat - both of which need an engineer rather than a DIY fix. Also worth considering: if your boiler is set lower than usual, or if you've recently had plumbing work carried out, the incoming water temperature may be affecting performance. It's a less obvious factor but it does come up, particularly in older properties.

Step 5 - Examine the Detergent Dispenser

A detergent dispenser that fails to open during the wash is a surprisingly common cause of poor cleaning, and it's often overlooked. The dispenser has a spring-loaded door that's designed to pop open at a specific point in the cycle. If a tall item in the lower basket is sitting directly in front of it, the door can't open and the tablet stays sealed inside throughout the whole wash.

Check that nothing in your lower basket is blocking the dispenser door. Then inspect the dispenser itself. Look for detergent residue or limescale build-up around the hinge or seal that might be preventing the door from springing open. Clean it with a damp cloth and a little vinegar if you see any build-up, and test the spring mechanism by pressing and releasing the door manually - it should snap back cleanly.

Step 6 - Rethink How You Are Loading the Machine

Loading pattern affects cleaning results more than most people expect. Dishes packed too closely together block water and detergent from reaching all surfaces. Large pots or pans placed in the lower basket can obstruct spray arm rotation. Cups and bowls placed right-side up collect dirty water rather than letting it drain away.

The basic rules: glasses and cups go upside down on the top rack; plates go in the lower rack facing the centre spray arm; pots and pans go on the sides or back at a slight angle so water can drain off. Don't overload. Bosch and Hotpoint both publish loading diagrams in their manuals and on their websites - these are genuinely useful if you've never looked at them before. If you're running a half-full machine and still getting poor results, loading isn't the issue, but it's always worth checking if you've recently changed your habits.

Step 7 - Run a Hot Maintenance Wash

Once you've cleaned the filter, cleared the spray arms, and topped up the salt and rinse aid, run an empty hot cycle - the 70-degree or "intensive" programme on your machine. Place a dishwasher cleaning tablet or a cup of white vinegar in the bottom of the tub (not in the dispenser). This flushes out grease, scale, and food residue from the pump, pipework, and internal walls.

If you use the Voltrade GoFIX diagnostic tool before booking a call-out, running this cycle and noting whether any error codes appear during it can help narrow things down significantly. If the machine completes the full cycle without interruption and the interior smells clean afterwards, the problem was almost certainly a build-up issue that this process has cleared.

What to Do If This Does Not Fix It

If you've worked through all seven steps and the dishwasher is still not cleaning properly, the fault is likely mechanical or electronic rather than a maintenance issue. The most common underlying causes at this stage include:

• A faulty wash pump or circulation pump failing to generate enough water pressure
• A failed heating element meaning the water never reaches the correct temperature
• A worn or cracked door seal allowing heat to escape during the cycle
• A partially blocked waste hose causing slow or incomplete draining
• A faulty water inlet valve restricting how much water enters the machine per cycle

Some of these can be narrowed down at home before you call anyone. If you can hear the pump running but cleaning is still poor, that points in a different direction to a machine that runs quietly but never seems to heat up. Note any error codes on the display. Bosch and Samsung machines both produce specific codes that can identify the fault before an engineer visits, which can save diagnostic time and, in some cases, call-out cost.

When to Stop and Call a Professional

Book an engineer rather than continuing with DIY checks if any of the following apply to your situation:

• You're seeing error codes that don't clear after a reset
• The machine is leaking water onto the kitchen floor
• There's a burning smell or the cycle stops unexpectedly partway through
• The door latch or door seal is visibly cracked or damaged
• You've cleaned the filter and spray arms and the results are still poor

A diagnostic visit from an appliance repair engineer covering the Weybridge and wider Surrey area typically costs between 60 and 100 pounds, including the call-out and initial assessment. If parts are needed, common repairs such as replacing a heating element, circulation pump, or inlet valve typically cost between 120 and 250 pounds for parts and labour combined. Always ask for a fixed quote before work begins.

If your machine is more than eight to ten years old, it's worth weighing up the repair cost against the price of a new mid-range dishwasher. LG and Samsung models often come with longer manufacturer warranties than older budget brands, and if yours is still within that window, it's always worth checking before paying for repairs out of pocket.

Questions About This Process

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

White residue is almost always caused by limescale or undissolved detergent. In hard water areas like Weybridge, limescale deposits on glassware are very common. Start by making sure your dishwasher salt is topped up and your rinse aid dispenser is full, then run a hot maintenance wash. If the problem continues after those steps, your internal water softener unit may need servicing or replacing - that's a job for an engineer.

How often should I clean my dishwasher filter?

If you run your dishwasher daily, rinsing the filter every two to four weeks is a sensible routine. If you notice dishes coming out with visible food residue or gritty deposits, check the filter straight away rather than waiting. Households in Surrey's hard water zones tend to see faster limescale build-up than the national average, so monthly cleaning and descaling of the filter is a practical baseline to work from rather than a worst case.

Is it worth repairing an old dishwasher or should I just replace it?

If your dishwasher is under six years old, repair is typically the better option provided the fault is identifiable and parts are available for your model. Beyond eight to ten years, you're often looking at diminishing returns - components become harder to source and other parts tend to follow once one fails. Get an engineer's diagnosis first, compare the repair quote against the cost of a new mid-range machine, and factor in that newer models are considerably more energy and water efficient than appliances from ten years ago.