Skip to content   Skip to footer navigation 

5 things CHOICE's dishwasher expert would never do

Our dishwasher geek explains why you shouldn't close your dishwasher door and why the tablet dispenser is dispensable. 

dishwasher cutlery stacked upright
Last updated: 17 January 2023
choices ashley iredale with dishwasher

Ashley knows a thing or two about dishwashers – including what not to do with them.

CHOICE whitegoods expert Ashley Iredale knows how to treat a dishwasher right to get the best results and keep it running happily. 

But sometimes it's the things you don't do that can make the biggest difference  to both your dishwasher and what you wash in it. 

We asked him to tell us about the biggest dishwasher no-nos: the things he doesn't do and never will. 

Here's what he said. 

1. He never puts the dishwasher tablet in the detergent dispenser

In good news for lazy housekeepers, Ashley says you can dispense with the dispenser – just throw the tablet in the bottom of the dishwasher and you're good to go. 

You'll get the same effect but you'll have saved yourself approximately 2.5 seconds of cursing at the fiddly closure. 

"Detergent dispensers are primarily designed for powdered detergents, and don't open until after the first rinse cycle – this prevents your powdered detergent from washing down the drain before the wash cycle starts," says Ashley. 

By having them loose in the tub from the get-go, it gives the dissolvable wrapper a head-start in the initial rinse

CHOICE dishwasher expert Ashley Iredale

"Tablets, however, are too big to wash away like that, and by having them loose in the tub from the get-go, it gives the dissolvable wrapper a head-start in the initial rinse, so the tablet itself is more readily available from the start of the wash cycle. 

"This is especially important if you're running a quick wash program, where there's less time for the detergent to work, or if you find the dishwasher tablet's wrapper hasn't dissolved by the end of the cycle."

person rinsing plate under tap

Pre-rinsing wastes water and won't get your dishes any cleaner.

2. He never pre-rinses the dishes

This one might surprise you, but giving your dishes a quick rinse before stacking them in the dishwasher can actually lead to dirtier, not cleaner, dishes. 

That's because pre-rinsing your dishes can effectively trick your dishwasher into thinking your plates are cleaner than they actually are, so it won't work as hard to wash your dishes. 

"By all means, scrape your dishes before putting them in the dishwasher, but there's no need to rinse – it won't make your dishes any cleaner and it'll just use more water," says Ashley. 

"Plus, by rinsing your plates clean before washing, you're showing a complete lack of faith in your dishwasher's ability to do the one job you paid all that money for it to do."

3. He doesn't put good knives in the dishwasher

If you want to keep slicing, dicing, chopping and julienning, the dishwasher is not the place for your good kitchen knives. 

Not only can all the bumping and rattling dull your knives' sharp edges, the harsh chemicals in dishwasher detergent and the hot, humid environment can corrode the high carbon steel in good quality chef's knives. 

"If you're going to spend money on good knives, don't chuck them in the dishwasher to save time – they're a handwash-only item," says Ashley. 

"Not to mention that a dishwasher full of sharp knives is an accident waiting to happen.

"It'll actually cost you more time, both in constantly sharpening your knives to restore the sharp cutting edge, and in first aid for the injuries you'll sustain from trying to cut food with a blunt blade."

But don't worry, your everyday plates and cutlery are safe in the dishwasher. If you're not 100% sure, check our list of what you can and can't wash in the dishwasher.

person handwashing a large knife

Knives are a handwash-only kitchen utensil.

4. He never runs the dishwasher if it's not completely full

A full dishwasher is an efficient dishwasher, says Ashley. Washing a half-full dishwasher (or half-empty, depending on your worldview!) is inefficient for a number of reasons. 

Firstly, you'll be using more water and energy on a plate-by-plate basis – your dishwasher will use around the same amount of electricity and water regardless of how full your dishwasher is. 

By rinsing your plates clean before washing, you're showing a complete lack of faith in your dishwasher's ability to do the one job you paid all that money for it to do

CHOICE dishwasher expert Ashley Iredale

Secondly, a full dishwasher dries better. Basically, the crockery heats up from the hot water in the machine, then it holds onto that heat, which helps it to dry. So the more you put in your machine, the more heat, and thus better drying. 

5. He doesn't close the dishwasher door in between washes

Yes, we know: leaving the door open can spoil the look of your otherwise-tidy kitchen. But do you know what else it can spoil? Your dishwasher. 

Leaving your dishwasher closed doesn't give the seals a chance to dry out, which gives mould and other nasty stuff (including the associated bad smells) a chance to take hold. 

You don't need to leave it wide open – just leaving it slightly ajar will do the trick. 

"It also pays to wipe your dishwasher's door seals down with a soft, damp cloth as part of your weekly cleaning routine to remove food scraps and keep dishwasher door seals in tip-top condition," Ashley says. 

We care about accuracy. See something that's not quite right in this article? Let us know or read more about fact-checking at CHOICE.

Stock images: Getty, unless otherwise stated.