Musty smelling washing machines can be refreshed with item already in your pantry - and no, it's not vinegar

There are few things more unpleasant than opening the washing machine to put on a load only to have a musty odour waft out.

The chances of that smell ending up on your clean clothes is pretty high, which is the last thing you want when washing clothes.

Thankfully, a plumber has revealed why that stink occurs and the very simple and affordable way to get rid of it.

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"The smell usually comes from trapped detergent residue, fabric softener, and lint mixing with warm, damp conditions," James Clarkson, a plumber with 15 years experience, told The Sun.

"This creates the perfect breeding ground for mould and bacteria. Once that builds up behind the drum or in the rubber seal, the machine can quickly start smelling."

To remove the smell Clarkson recommends baking soda (also known as bicarb soda) as it is deodorises and is mildly abrasive.

"When you run it through the machine, it helps break down soap scum and neutralises odours without damaging the drum or pipes," he said.

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Baking soda is a common pantry staple that is already in most kitchens, but if you don't have it on hand it is available quite cheaply at the supermarket.

The best value baking soda is at Coles where you can find a 1kg bag for just $3.50, meanwhile Woolworths sells a 500g bag for $2.45. Smaller amounts are also available.

To clean your washing machine add half a cup of baking soda into the drum and then run a hot cycle.

This task should be done monthly to keep the washing machine smelling fresh.

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The drum isn't the only part of the washing machine that can develop a musty odour, detergent dispenser drawers and, in front loaders, the rubber door seal can too.

Moisture and detergent residue can get left behind and trapped in both which can lead to mould.

To clean these parts Clarkson said to use a cloth soaked in hot soapy water and vinegar to wipe them out.

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You can prevent any buildup from occurring in the door seal by wiping the door seal with a cloth after each use.

The detergent drawer can also be wiped dry or you can remove the drawer completely, tip out any water and leave the space to dry until the next time you need to use the machine.

It also helps to keep the washing machine door open after use so that the drum can thoroughly dry out.

Using less detergent than you think you need, which is about one to two tablespoons, also helps prevent musty odours and mould as excess detergent leaves behind residue on the drum.

If you're doing that and can still notice a bad odour then check the washing machine filters.

Front loader filters are at the bottom front of the machine, usually near the corner and need emptying regularly.

In top loaders filters are inside the drum and need emptying after each use to remove the wet lint collected during a cycle. If not emptied and left inside the appliance this lint remains damp and keeps building up leading to mould and and a nasty odour.

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