Dishwasher Not Cleaning Properly - What to Check According to Barnsley Engineers

Published October 2026 | Dishwasher Not Cleaning Properly

We asked our Appliance Repair engineers the questions Barnsley homeowners ask most about why their dishwasher isn't cleaning properly - and what they can do about it before calling anyone out.

Why Isn't My Dishwasher Cleaning Dishes Properly Any More?

A dishwasher relies on three things working together: hot water at the right temperature, effective detergent, and sufficient spray pressure. When any one of those breaks down, cleaning performance drops. In most cases, the problem isn't a major mechanical fault - it's something that has developed gradually and gone unnoticed.

The most common causes our engineers find are a blocked filter, clogged spray arm holes, an empty rinse aid dispenser, or water that isn't reaching the correct wash temperature. Less commonly, it's a failing water inlet valve or a worn circulation pump. We see all of these regularly across Barnsley and the wider South Yorkshire area, and several of them are things a homeowner can check and sort without a call-out.

If you're not sure where to start, the Voltrade GoFIX diagnostic tool asks a series of questions about your machine's symptoms and helps narrow down the likely cause - which saves time when you do eventually need an engineer.

How Do I Clean the Dishwasher Filter and Why Does It Matter?

The filter is the single most commonly neglected part of any dishwasher, and a blocked filter accounts for a large proportion of the "not cleaning properly" calls we receive. It sits at the base of the machine - beneath the lower spray arm - and catches food debris before it can be recirculated around the tub. Once it's clogged, dirty water goes back over your dishes with every wash cycle.

Here's how to clean it:

1. Pull out the lower rack to access the base of the machine.
2. Twist and lift the filter assembly - most Bosch, Hotpoint, and Beko models have a two-part filter, with a coarse outer mesh and a finer inner cylinder.
3. Rinse both parts under warm running water. Use a soft brush - an old toothbrush works well - to remove stubborn deposits from the mesh.
4. Check the sump area underneath the filter for any loose food debris and wipe it clear.
5. Replace the filter and make sure it locks back into position properly.

Monthly maintenance like this prevents the most common causes of a dishwasher not cleaning effectively and keeps water flowing at full pressure through the spray arms. If the filter looks cracked or the mesh is torn, a replacement is typically inexpensive - between 10 and 25 pounds for most models.

Could Blocked Spray Arms Be Causing the Problem?

Spray arms distribute hot water around the wash tub during a cycle. Each arm has a series of small holes, and those holes gradually block with limescale, food residue, and detergent build-up - particularly in areas with moderately hard water, which applies to parts of South Yorkshire. When holes are blocked, water pressure drops and whole sections of the load don't get hit properly.

To check them, remove the spray arms (they typically unclip or unscrew counter-clockwise) and hold each one up to the light. Look through every hole and use a cocktail stick or a piece of stiff wire to clear any blockages. Rinse each arm under warm water while spinning it to flush debris out completely. Then reinstall and check that each arm spins freely on its bearing - a stiff or wobbly arm won't distribute water evenly regardless of how clear the holes are.

If the arms themselves are cracked or the bearings are worn, replacements cost between 10 and 30 pounds depending on the brand. Running a dedicated dishwasher descaler through an empty cycle every couple of months keeps limescale from building up in the spray arms and along the internal walls of the machine.

Is the Water Temperature Hot Enough to Clean Properly?

Dishwashers typically heat water to between 50 and 65 degrees Celsius on a standard wash cycle. At those temperatures, grease breaks down and the enzymes in modern detergents activate properly. If the heating element or thermostat fails, the water won't get hot enough - and your dishes will come out looking cleaned but feeling greasy even after a full cycle.

Two signs that temperature is the likely issue: the detergent tablet is still partially intact at the end of a wash, or the inside of the machine feels warm rather than very hot when you open it immediately after a cycle finishes. Both suggest the water isn't reaching wash temperature.

Diagnosing a heating element or thermostat fault requires an engineer with a multimeter. The component itself typically costs between 20 and 60 pounds, and with labour the total repair usually falls between 80 and 150 pounds. For a machine under 10 years old, that's nearly always a worthwhile repair. Older Hotpoint and Beko machines from the early-to-mid 2010s are the ones we most commonly see with heating element failures at this point in their lifecycle.

Am I Using the Right Detergent and Rinse Aid?

Detergent and rinse aid perform different jobs, and you need both working correctly. Detergent handles the cleaning; rinse aid reduces surface tension in the final rinse so water sheets off glassware cleanly instead of pooling and leaving spots and streaks. Using just one, or running low on either, noticeably affects results.

Things to check:

• Make sure the detergent dispenser door actually opens during the cycle. If the spring mechanism is stiff or a tall item in the lower rack is blocking the door, the tablet never gets released. This is a very common and easily missed cause of poor cleaning.
• Check the rinse aid level. Most machines have a small window or warning light. If you've let it run empty, cloudiness on glassware is almost guaranteed.
• All-in-one tablets include rinse aid, but their performance on short or cool cycles isn't always reliable. Using separate liquid rinse aid typically gives cleaner results, especially on glassware.
• Store tablets in a dry place. Tablets that have absorbed moisture from a damp cupboard won't dissolve cleanly or at the right point in the cycle.

If cloudiness persists despite a full rinse aid reservoir, increase the dosage setting on the machine. Bosch models have an adjustment dial on the inside of the door panel; Samsung and LG machines usually bury this setting in the options menu. Increasing rinse aid dosage by one or two steps often resolves persistent spotting on glasses without any other changes.

Could a Faulty Water Inlet Valve Be Affecting Performance?

The water inlet valve controls how much water enters the machine at the start of each cycle. If the valve is partially blocked, scaled up, or the solenoid is beginning to fail, the machine won't fill to the correct level. A dishwasher that isn't carrying enough water won't clean properly - there simply isn't enough circulating through the spray arms. You might also notice error codes related to water fill, or the machine taking longer than usual before the wash phase begins.

Low household water pressure can produce the same symptoms, though this is less common in most Barnsley properties connected to the mains supply. One check you can do yourself is to look at the supply hose at the back of the machine - confirm the isolation valve is fully open and the hose isn't kinked or pressed against the wall behind the appliance.

If the valve itself is the problem, an engineer will inspect the inlet filter mesh (a small screen that can trap debris from the water supply) and test the solenoid with a meter. Inlet valve replacement typically costs between 50 and 120 pounds all in, and the job usually takes under an hour.

Does How I Load the Dishwasher Actually Make a Difference?

It makes a bigger difference than most people expect. A significant number of the calls our engineers attend turn out to be machines in perfect working order - the problem is how they're being loaded. Poor loading blocks spray, traps water in cups and bowls, and prevents detergent from reaching the dishes that need it most.

Loading principles that make a real difference:

• Face plates, bowls, and pots inward and downward so the spray hits the dirty surface directly rather than the clean outside.
• Don't nest items - cups stacked inside each other trap water and block spray from reaching either one properly.
• Keep tall items, particularly pan handles, away from the spray arm rotation path. A single handle poking through the rack can stop an arm spinning entirely for an entire cycle.
• Heavily soiled items belong on the lower rack, which receives the most intense spray pressure.
• Avoid overloading. A machine packed to the limit will consistently underperform compared to one loaded at around 70 to 80 percent capacity.

Also check that nothing in the lower rack is blocking the detergent dispenser door from swinging fully open. If the tablet can't be released at the right point in the cycle, the wash will be weak regardless of everything else. It's one of the first things to rule out when cleaning performance has dropped without any obvious mechanical change.

When Should I Stop Troubleshooting and Call an Engineer?

There's a clear line between what a homeowner can reasonably sort and what needs a trained engineer. Filter cleaning, spray arm clearing, rinse aid refills, checking the dispenser door, and adjusting loading - all of that is worth working through first. Beyond those basics, it's usually better to get a professional in.

Call an engineer if:

• The machine is showing error codes that don't clear after a reset and a power cycle.
• Dishes are coming out cold at the end of a full cycle, pointing to a heating element fault.
• The machine isn't filling, draining, or completing a full cycle.
• You can hear grinding or unusual humming from the pump area during a wash.
• There's water pooling under the machine or leaking around the door seal.

Most appliance engineers covering the Barnsley and South Yorkshire area charge a call-out fee of between 50 and 80 pounds, which typically includes the diagnosis. Additional parts and labour costs depend on the fault. A good engineer will give you an honest assessment of whether the repair is economic given the age and condition of the machine - and won't recommend parts that aren't needed.

How Much Does a Dishwasher Repair Typically Cost in Barnsley?

Repair costs vary considerably depending on the fault and the brand of machine. Here are the ranges Barnsley homeowners can typically expect:

• Call-out and diagnosis: 50 to 80 pounds
• Filter or spray arm replacement: 30 to 80 pounds including labour
• Door latch or dispenser mechanism: 40 to 90 pounds
• Water inlet valve replacement: 50 to 120 pounds
• Heating element replacement: 80 to 150 pounds
• Circulation pump replacement: 100 to 200 pounds
• Control board replacement: 150 to 300 pounds (rarely economic on older machines)

Parts availability varies by brand. Bosch, Hotpoint, and Beko have widely available spares at competitive prices with short lead times. Samsung and LG parts can sometimes take longer to source, which may affect how quickly a repair gets completed. Always ask for a fixed price before authorising any work, and make sure the engineer has confirmed the specific fault before ordering anything.

How Do I Keep My Dishwasher Cleaning Well Long-Term?

Dishwashers that receive regular basic maintenance consistently outperform neglected ones and commonly reach 12 to 15 years of reliable use. Most of the maintenance involved takes only a few minutes a month.

A simple routine our engineers recommend:

1. Clean the filter every three to four weeks.
2. Check and clear spray arm holes monthly.
3. Run a combined descaler and degreaser through an empty hot cycle every one to two months.
4. Wipe the door seal with a damp cloth monthly to prevent mould and odour build-up in the rubber.
5. Keep the rinse aid topped up at all times, and check dishwasher salt if your machine has a built-in water softener.
6. Match the wash programme to the load - running economy cycles for heavily soiled dishes means the machine never quite finishes the job, while running long hot cycles for light loads wastes energy unnecessarily.

For Barnsley homeowners who keep up with this kind of routine and still find their machine isn't performing well, the cause is typically a component that has worn gradually over time - something the Voltrade GoFIX tool can help identify before an engineer visits, so the call-out is efficient and focused.

A well-maintained dishwasher is one of the more reliable appliances in the home. When problems do arise, catching them early - through regular checks or a quick diagnostic - usually means a less expensive repair and far less disruption.