Dishwasher Not Cleaning Properly - What to Check in Altrincham

Published September 2026 | Dishwasher not cleaning properly what to check

We asked our Appliance Repair engineers the questions Altrincham homeowners ask most. From plates covered in food residue to glasses coming out cloudier than they went in, a dishwasher that is not cleaning properly is one of the most common calls we receive across Altrincham and the wider Greater Manchester area.

Why are my dishes coming out dirty even after a full wash cycle?

This is the most common question we hear, and the answer is rarely a single cause. In most cases, dishes coming out dirty points to a combination of factors - a blocked filter, low water temperature, or detergent that is not dissolving properly. Think of it this way: your dishwasher relies on three things working together - hot water, sufficient pressure through the spray arms, and effective detergent. If any one of those breaks down, the whole wash suffers.

Start with the obvious. Is the machine actually completing its cycle? Some Bosch and Hotpoint models will stop mid-cycle and display an error code without making much fuss about it. Check the display panel before assuming the cycle ran correctly. Next, open the dishwasher immediately after a cycle and feel whether the interior is hot. If it is cold or barely warm, temperature is likely your first problem. If it is hot but dishes are still dirty, move on to checking the spray arms and filter - those are almost always where the answer lies. Do not skip this step before calling an engineer, because these checks resolve the problem in a significant number of cases without any repair needed at all.

Could a blocked spray arm be causing the problem?

Yes, and this is more common than most people realise. The spray arms - typically two or three in a standard machine, located at the bottom, sometimes in the middle rack, and occasionally near the door - rotate and push pressurised water onto your load. If the small jets get clogged with limescale, food debris, or grease, water pressure drops and coverage becomes patchy. The result is that some dishes come out clean while others sitting in the blind spots do not.

To check the spray arms, remove them - most simply unclip or unscrew by hand - and hold them up to the light. You should be able to see clearly through each jet hole. If they look blocked, use a toothpick or thin piece of wire to clear each one, then rinse under a tap. On LG and Samsung machines, the spray arms can be scrubbed with a soft brush under warm water. It takes about ten minutes and costs nothing. Ideally, do this every two to three months as preventative maintenance rather than waiting until wash quality drops. If the arms are cracked or warped, replacements are inexpensive and easy to fit yourself - a new spray arm for most mid-range dishwashers typically costs between 15 and 35 pounds online.

How do I clean a dishwasher filter properly?

The filter is the single most neglected part of a dishwasher, and it is frequently the root cause when a machine stops cleaning well. Its job is to catch food particles so they are not recirculated through the wash water. When it gets clogged, dirty water gets sprayed back onto your dishes - which explains that greasy film or small food fragments you find on otherwise clean plates.

Here is how to clean it properly:

1. Pull out the bottom rack and locate the filter assembly at the base of the tub. It usually consists of a cylindrical mesh filter and a flat filter plate beneath it.
2. Twist the cylindrical filter anti-clockwise and lift it out, then remove the flat plate underneath.
3. Rinse both parts under warm running water. Use a soft brush - an old toothbrush works well - with a small amount of washing-up liquid to scrub away grease and debris.
4. Avoid abrasive scourers, as these can damage the mesh and reduce filtration efficiency over time.
5. Reinstall both parts and make sure the cylindrical filter locks back into position securely.

For most households, cleaning the filter once a month is sufficient. If you are running the machine daily or cooking frequently with sauces, consider doing it fortnightly. Beko and Hotpoint filters in particular tend to clog quickly if plates are not scraped before loading.

Why does my dishwasher leave a white film or residue on glasses?

White film on glassware is nearly always caused by one of two things: limescale build-up or insufficient rinse aid. In Greater Manchester, water hardness varies by area but is generally moderate to hard. Altrincham sits in a zone where limescale can absolutely be a problem if you are not using rinse aid regularly or keeping the salt topped up in the machine's softener reservoir.

Rinse aid lowers the surface tension of water so it sheets off dishes rather than leaving droplets that dry into white spots. If you have run low, that is commonly the first thing to show up on glassware. Check the rinse aid indicator on your machine - most Bosch and Siemens models have a small window on the door that shows the level at a glance.

Dishwasher salt is equally important in hard water areas. It regenerates the internal water softener and prevents limescale from accumulating inside the machine and on your crockery. Many people skip the salt entirely when using all-in-one tablets, but in harder water areas this is often not enough on its own. Try adding dedicated salt and adjusting the water hardness setting in your machine's menu - you will typically find this in the programme settings, and the manual will guide you to the right level for your postcode. Most modern dishwashers from Bosch, LG, and Samsung make this adjustment straightforward to find, and it can make a noticeable difference within a few cycles.

Could the water temperature be affecting wash performance?

Absolutely. Dishwashers are designed to wash at specific temperatures - typically between 50 and 75 degrees Celsius depending on the cycle selected. At lower temperatures, grease does not dissolve properly and detergent cannot activate fully. If your dishwasher seems to be running cool, there are a couple of likely causes worth investigating before calling anyone out.

The heating element, which heats the water to the correct wash temperature, can fail over time. This is a reasonably common repair on older machines, particularly budget models and heavily used Beko appliances. An engineer can test the element with a multimeter - if it shows no continuity, it needs replacing. A heating element replacement typically costs between 80 and 160 pounds including parts and labour, depending on make and model.

The thermostat or NTC sensor can also drift out of calibration, causing the machine to think it has reached the target temperature before it actually has. Our engineers use the Voltrade GoFIX diagnostic tool to check live sensor readings against the machine's reported values - this quickly identifies whether the control board, thermostat, or element is at fault without unnecessary guesswork, and means you get an accurate repair quote rather than a speculative one.

Is the detergent or rinse aid really making that much difference?

More than most people expect. The type, quantity, and condition of your detergent all matter. Here are the most common detergent-related problems we come across during callouts:

Using too much detergent can leave a sticky residue on dishes that actually attracts more dirt in subsequent cycles. Using too little, or using detergent that has gone stale - tablets that have absorbed moisture and clumped together in a damp cupboard under the sink - means the wash is underpowered. Store tablets in a cool, dry place and check the packaging date if your machine has recently started underperforming.

The dispenser door itself can also be the problem. If it is not opening at the right point in the cycle, the detergent drops to the bottom of the machine and washes away before the main wash stage begins. Check that nothing in the bottom rack is blocking the dispenser door when it swings open. On certain Samsung and LG machines, a faulty dispenser spring or latch is a known issue - it is a minor repair and relatively inexpensive, but one that makes a significant difference to cleaning results across the whole load.

How does hard water in Greater Manchester affect a dishwasher long-term?

Hard water is one of the bigger contributors to dishwasher wear in this part of the country. Over time, limescale accumulates on the heating element, inside the pump housing, and along the spray arm jets. This reduces efficiency, forces the machine to work harder to reach temperature, and can eventually lead to pump failure or element burnout well before the machine should reasonably need replacing.

The best defence is using dishwasher salt consistently, keeping rinse aid topped up, and running a descaling programme every few months. Most modern dishwashers have a dedicated cleaning cycle in their menu - check your manual. Alternatively, run an empty hot cycle with a proprietary dishwasher cleaner tablet, which helps dissolve limescale and grease from internal components that you cannot reach by hand.

For Altrincham homeowners with older machines showing signs of heavy internal scaling - reduced wash temperature, unusual noises during the cycle, or a burning smell when running - an engineer can descale the heating element and pump as part of a service visit. This is often considerably cheaper than replacing parts that have been damaged by untreated scale over several years, and can add meaningful life to an otherwise sound machine.

Can loading habits really affect how well a dishwasher cleans?

Yes, significantly. Loading habits account for more underperformance complaints than most homeowners expect. Here are the most common mistakes we see during callouts that turn out to have nothing to do with a mechanical fault:

1. Nesting bowls or cups so water cannot reach all surfaces. Always load cups upside down and at a slight angle so water drains away rather than pooling.
2. Placing large items in the bottom rack that block the spray arm from rotating freely. Give the arm a manual spin before closing the door to check it has a clear path.
3. Overloading the machine. Every item needs to be within line of sight of at least one spray arm. Cramming the machine might feel efficient but it reduces wash quality across the entire load.
4. Putting heavily soiled pots and pans in the top rack, where water pressure is lower. Heavily soiled items belong in the bottom rack, facing towards the centre of the machine where spray coverage is strongest.

A small change in loading technique can sometimes resolve a cleaning problem entirely, with no repair involved at all. It is always worth ruling this out first.

When should I call an engineer rather than troubleshooting myself?

There are clear signs that it is time to call a professional. If your machine is displaying a persistent error code that resets but keeps returning after a few cycles, that typically points to a failing component rather than a user issue. If you can hear the machine running but little or no water seems to be circulating through the wash, the circulation pump may be failing - this is not a DIY repair and attempting it without the right tools can make things worse.

Water leaking from the door seal or from underneath the machine should also prompt a professional call without delay. Leaks can damage flooring and cabinetry quickly, and the cause is not always a simple worn seal - it can also indicate a blocked drain pump causing water to back up and overflow internally.

Our engineers use the Voltrade GoFIX diagnostic tool during callouts, which gives a clear picture of not just the fault you called us about but any other components showing early signs of wear. That way you can make an informed decision rather than fixing one thing only to have a second part fail a month later. Across Altrincham, diagnostic callout fees typically run between 60 and 90 pounds, with repairs quoted separately once the fault is confirmed.

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

Our engineers get asked this regularly, and the answer depends on a few practical factors. The general rule is this: if the repair costs more than half the price of an equivalent new machine, replacement starts to make financial sense. For a budget machine that cost 300 pounds new, a repair quote of 180 pounds is a harder call. For a higher-end Bosch or Miele that cost 900 pounds new, the same 180-pound repair is almost always worth doing.

Age matters too. Most dishwashers are built to last around ten years with reasonable maintenance. If your machine is eight or nine years old and showing its first significant fault, a repair can realistically give you another two to three years of reliable service. If it is the same age but this is the third or fourth fault in twelve months, the economics shift towards replacement.

Whatever you decide, the key is getting an accurate diagnosis first rather than guessing at parts. A proper assessment tells you the condition of the whole machine, not just the presenting fault, so the decision you make is based on the full picture rather than an optimistic repair that leaves underlying problems untouched.

Most dishwasher cleaning problems in Altrincham homes come down to a blocked filter, scaled spray arms, low rinse aid, or a combination of all three - none of which require a repair engineer. Start with those checks, review your loading habits, and make sure salt and rinse aid levels are correct for your water hardness. If those steps do not resolve the issue, a diagnostic callout will quickly identify whether the fault lies with the pump, heating element, control board, or dispenser. Keeping on top of basic maintenance is always cheaper than a repair bill, and in a hard water area like Altrincham that maintenance discipline pays off over the life of the machine.

How often should I clean my dishwasher filter?

For most households running the dishwasher daily, cleaning the filter once a month is a good baseline. If you cook frequently with sauces or do not scrape plates before loading, fortnightly cleaning will maintain wash quality and prevent food debris from being recirculated back onto your dishes during the cycle.

Why does my dishwasher smell even after it has run a full cycle?

Odours inside a dishwasher are almost always caused by food debris trapped in the filter, around the door gasket, or in the drain pump. Clean the filter thoroughly, wipe down the rubber door seal with a damp cloth, and run an empty hot cycle with a dishwasher cleaning tablet to flush residue from internal components that you cannot reach by hand.

Can I use washing-up liquid instead of dishwasher tablets in an emergency?

No - this is a common mistake that can cause a significant foam overflow inside the machine and potentially damage the pump seals. Washing-up liquid produces far too many suds for a dishwasher's sealed environment to handle. If you run out of detergent, it is better to hand wash the load than to substitute with washing-up liquid.

How much does a dishwasher repair typically cost in Altrincham?

Diagnostic visits from a local appliance engineer in the Altrincham area typically cost between 60 and 90 pounds. Common repairs such as a new heating element, drain pump replacement, or spray arm assembly usually add between 50 and 130 pounds in parts and labour, depending on the brand and the availability of parts for your specific model.