Your Dishwasher's Anatomy: A Guide to Key Components

Something is wrong with your dishwasher. Dishes are coming out dirty, water is pooling on the floor, or the machine just won’t drain. Before you call someone or start looking at new machines, it’s worth knowing what’s inside. Almost every time, it’s one part that’s failed. Not the whole appliance. At Steve’s Appliance Spares, we’ve helped over 150,000 Kiwis find the right part for brands like Fisher and Paykel, Bosch, Samsung, and more. This guide walks you through what each part does, how to spot when it’s failing, and what to do about it.

This guide walks you through the key parts inside a home dishwasher, what each one does, how to spot when it's failing, and where to find a replacement. Every part linked here is one Steve's Appliance Spares stocks and dispatches nationwide from our Palmerston North warehouse. Browse the full dishwasher parts range for your model.

1. Dishwasher hoses

Often overlooked, dishwasher hoses do two essential jobs: bringing water in and taking dirty water out. When a hose fails, you usually notice it as either a leak, a drainage problem, or unusual noises during the cycle.

Types of hose

• Inlet hose. Supplies fresh, clean water from your home's plumbing into the dishwasher during a cycle. Connects between the cold water tap under the sink and the dishwasher.

• Drain hose. Carries dirty water away after each wash and rinse cycle, directing it to your sink's drain or waste connection.

When they need attention

• Pooling water under the dishwasher or around the base

• Slow drainage at the end of the cycle

• Unusual gurgling or rattling noises while it runs

• Visible cracks, kinks, or worn spots on either hose

Hoses can develop leaks, cracks, or kinks over time. A small leak left alone turns into a bigger one, and a kinked drain hose can stop the machine draining completely. Replacement is usually a straightforward job once the dishwasher is pulled out for access.

2. Basket racks

The dishwasher racks are the workhorses of the machine, holding your dishes, glasses, cutlery and utensils securely while they're blasted with water and detergent. Most dishwashers have an upper and a lower rack, often with adjustable or fold-down sections.

When they need attention

• Rust forming on the rack tines (the wires that hold dishes)

• Broken or bent tines that no longer hold plates upright

• Warping that makes the rack sit unevenly or jam in the cabinet

• Coating peeling off the tines, exposing bare metal underneath

Minor surface rust can sometimes be touched up with rack repair coating. More serious damage means it's time for a replacement, both for cleaning performance and to stop rust marks transferring onto your dishes.

3. Door seals

The dishwasher door seal is a rubber or plastic gasket that runs around the dishwasher door. Its job is simple but essential: when the door is closed, the seal creates a watertight barrier that keeps water and steam inside the machine where they belong.

When they need attention

• Water leaking from the base of the door during a cycle

• Visible cracks, splits, or tears in the rubber

• The seal feels brittle, hard, or has lost its flexibility

• The seal has come loose from its channel

• Mould or grime in the seal that won't clean off

Door seals harden and crack over time, especially with regular heat and detergent exposure. A failed seal is the most common cause of dishwasher leaks. Replacement seals push into a channel around the door and can usually be swapped by hand.

4. Basket wheels and rollers

Small parts, big difference. Dishwasher wheels (also called rollers) sit on the bottom of the racks and let them slide smoothly in and out on their rails. When they break or jam, loading and unloading turns into a constant battle.

When they need attention

• The rack feels stiff or sticks when you slide it out

• A wheel has come off completely, leaving the rack lopsided

• A wheel won't spin, even after cleaning

• The rack jumps or jams part-way along the rail

Food debris can build up around the wheels and stop them spinning. Try cleaning them first. If the wheel itself is cracked, missing, or worn flat, replacement is a simple clip-on or push-on job.

5. Filters

The dishwasher filter sits at the bottom of the tub. It traps food debris during the wash, stopping it from cycling back onto your supposedly-clean dishes. Filters usually come as a fine mesh screen wrapped around a larger plastic component.

When they need attention

• Cycles take longer than they used to

• Dishes come out with bits of food stuck to them

• Cleaning performance has dropped overall

• An unpleasant smell from the dishwasher when the door is opened

• Visible food buildup or grease on the filter when you check it

A clogged filter is one of the most common causes of poor dishwasher performance. It’s also the fault we hear about most from customers across NZ, and the fix is almost always a clean or a cheap replacement. Most filters lift out by twisting and pulling. Rinse under running water until clear, scrub gently with a soft brush if needed, and refit. If the filter mesh is torn or the plastic is cracked, replace it. Browse our range of replacement dishwasher filters and email steve@appliancespares.nz with your model number if you need help finding the right one.

6. Spray arms

The spray arms are the rotating sprinklers that fire water onto your dishes from above and below the racks. Most dishwashers have at least two, an upper arm under the top rack and a lower arm in the base of the tub.

When they need attention

• Dishes on one side come out cleaner than the other

• You can hear the spray arm hitting a tall pot or utensil during the cycle

• The arm doesn't spin freely when you push it by hand

• The spray holes look clogged with limescale or food debris

• A worn bearing where the arm meets the tub

Check the spray arms can rotate freely. Use a toothpick or wire to clear any blocked spray holes. If an arm is cracked, won't spin, or has lost a spray cap, browse our full dishwasher parts range for a replacement.

Troubleshooting common dishwasher problems

Four faults come up most often. Here's how to work through each one.

Dishes aren't coming out clean

Run through these checks in order:

1. Clean the filter. A clogged filter is the most common cause of dirty dishes.

2. Check the spray arms can rotate freely. Push them by hand. Clear any blocked spray holes with a toothpick.

3. Make sure you're using the right wash cycle for the level of soiling. Heavy loads need a longer, hotter cycle.

4. Check the rinse aid and detergent dispensers are working and filled with the right products.

Dishwasher won't drain

Likely causes: a clogged filter, a kinked or blocked drain hose, or a faulty drain pump.

Fix: clean the filter, straighten and check the drain hose for blockages, and if the machine still won't drain, suspect the pump. Pumps are an electrical part and should be replaced by a qualified technician.

Loud noises during the cycle

Most common causes: a worn spray arm bearing, an object (like a piece of cutlery) stuck in the impeller at the bottom of the tub, or a failing pump.

Fix: cancel the cycle, open the machine, and check for anything stuck at the base of the tub. Check the spray arms spin smoothly. If the noise is constant and seems to come from the motor area, call a technician.

Dishwasher is leaking

Usual suspects: a worn door seal, a leaky inlet or drain hose, or a worn or cracked spray arm. Check the seal first, it's the most common cause and the easiest to inspect.

Habits that keep your dishwasher running well

Five simple habits cut how often you need replacement parts:

• Clean the filter regularly. Once a month, lift it out, rinse under running water, and refit. This is the single biggest thing you can do to prevent dishwasher problems.

• Clear the spray arms. Make sure they spin freely and the spray holes aren't blocked with limescale or food debris.

• Check the spray arm holes. Once a month, give them a quick look. Limescale and food debris build up in the small holes over time. A toothpick clears them in seconds and keeps water reaching every part of the load.

• Run a vinegar cycle. Once every month or two, run an empty hot cycle with a cup of white vinegar on the bottom rack. Cuts mineral buildup and kills off any smells.

• Scrape, don't pre-rinse. Scrape large food off plates before loading, but don't pre-rinse them. Modern dishwashers need some food residue to work properly.

DIY repair or call a professional?

Some dishwasher parts swap out easily by hand. Others need a qualified technician under NZ rules. Here's a clear guide:

Fitting dishwasher parts safely

 Important: Only fit these parts yourself if you have experience installing this kind of part. If you do not have that experience, hire a professional to do it.

Most user-replaceable dishwasher parts, including filters, wheels, seals and racks, are no-tools, no-risk jobs. Just turn the machine off first and let it cool.

Anything electrical, including the drain pump, inlet valve, control board, and wiring, must be done by a qualified, licensed technician under New Zealand rules. The same applies to plumbing connections at the wall. If you're not sure which kind of repair yours is, email Steve's Appliance Spares before you start.

Finding the right replacement part

Knowing your dishwasher's model number is the single most important step when ordering parts. Parts vary a lot between brands and models, and a part that looks close can fit a different machine entirely.

Where to find your model number

• On a label on the side of the door

• Around the door frame when the door is open

• On the underside of the kickplate at the bottom of the machine

• In the user manual

Write the model number down exactly, every letter, number and dash. If you can't find it, email us a photo of your dishwasher and we'll help you identify the model.

Where to buy dishwasher parts in NZ

Steve's Appliance Spares stocks dishwasher parts NZ-wide for all the major brands. Dispatched from our Palmerston North warehouse with New Zealand Post and New Zealand Couriers. Trusted by over 800 service companies, electrical wholesalers, suppliers and servicemen.

Browse by part type:

• Dishwasher Hoses, for inlet and drain hoses

• Dishwasher Seals, for door and tub seals

• Dishwasher Filters, for replacement filters

• Drain Pumps, for dishwasher and washing machine drain pumps

• All Dishwasher Parts, to browse the full range for your brand and model

Frequently asked questions

Why are my dishes not coming out clean?

The most common cause is a clogged filter. Lift it out, rinse it under running water until clear, and refit. If that doesn't fix it, check the spray arms can rotate freely and clear any blocked spray holes. Also make sure you're using the right wash cycle for the load.

Why is my dishwasher leaking from the bottom?

Most leaks come from a worn door seal. Check the seal around the door for cracks, splits, or brittleness. Other possibilities are a leaky hose or a cracked spray arm. Inspect the seal first, it's the easiest to check and the most common cause.

How often should I clean my dishwasher filter?

Once a month under normal use. If you don't pre-rinse heavily soiled dishes, clean it more often. A clogged filter is the single biggest cause of poor dishwasher performance, so this small habit prevents most of the common faults people email us about.

Can I replace dishwasher parts myself?

For filters, wheels, racks, seals, and spray arms, yes, these are user-replaceable parts and most swap out by hand. For drain pumps, inlet valves, control boards, and any wiring or plumbing repairs, hire a qualified technician. Under NZ rules, electrical work has to be done by someone licensed. Browse our full dishwasher parts range to see what's available for your model.

How do I find my dishwasher's model number?

Look on the side of the door, around the door frame when open, on the underside of the kickplate, or in the manual. Write the full code down exactly, every letter and number. The model number is the most important piece of information when ordering parts.

How long should a dishwasher last?

A well-maintained dishwasher typically lasts 10 to 15 years. Regular filter cleaning, occasional vinegar cycles, and replacing wearing parts on time (seals, wheels, filters) all extend its life significantly. Most dishwashers that get replaced too early die because of one neglected part, not because the whole machine is finished.

Need help finding the right dishwasher part?

Not sure which part you need, or which dishwasher model you've got? Email steve@appliancespares.nz with your model number and a description of the fault, and Steve's Appliance Spares will point you to the right dishwasher part before you order. Shipped nationwide from our NZ warehouse.

About Steve's Appliance Spares

Steve's Appliance Spares is a New Zealand owned and operated parts supplier based at 731C&D Tremaine Ave, Palmerston North, 4414. Operated by an appliance industry expert, the business supplies spare parts nationwide to the NZ public and to over 800 service companies, electrical wholesalers, suppliers and servicemen. The range covers dishwashers, washing machines, fridges, ovens, vacuum cleaners, coffee machines, microwaves and more, dispatched with New Zealand Post and New Zealand Couriers for the fastest affordable options available.