A guide to rinse aids and dishwasher salts

From whether you need rinse aids to understanding the purpose of dishwasher salt, we’ve put together a guide answering every question you might have. 

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To get your glassware gleaming, your dishwasher needs more than just a water supply. This is where dishwasher salt and rinse aid come in.

But are they both necessary? How do they work and how should they be used to keep your dishwasher working at its best?

We’ve looked at the most searched-for questions around dishwasher salt and rinse aid.

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What is rinse aid?

It’s all in the name. Rinse aid helps water rinse off your dishes and glasses. It does this by reducing the surface tension of water, stopping it from sticking to surfaces as easily and helping it to drain away.

Where water can’t stick to surfaces easily, you get fewer water marks — keeping your glasses and utensils streak free. In hard water areas especially, rinse aid helps prevent water spots from forming and makes dishes dry faster too.

Do you need rinse aid?

It’s not as necessary as cleaning tablets and salt but if you want to avoid streaks and watermarks, it’s important.

In 2017, it became a legal obligation to reduce the volume of phosphates in dishwasher detergent. Phosphates are a great cleaning agent but they’re harmful to the environment. So, by reducing the levels in dishwasher tablets, there’s less impact on an environmental level, but the detergent is less effective too.

Where does rinse aid go in your dishwasher?

The rinse aid compartment is usually found on the inside of the dishwasher door, next to the detergent compartment. You should see a symbol that shows lines (representing water) flowing in a downward direction.

Depending on how many washes you do, you might have to fill up the rinse aid every few weeks. When doing so, carefully pour the rinse aid into the dispenser until it reaches the max line.

Do I need dishwasher salt?

Dishwasher salt is course-grained sodium chloride, which helps soften hard water.

Hard water contains high levels of calcium carbonate, also known as lime. In a dishwasher, it can lead to limescale build-up on the filter and potentially damage the appliance. 

Not using enough dishwasher salt, therefore, could cause your dishwasher to break down more easily or need recurring dishwasher repairs and maintenance.

If you find that your dishes are coming out streaky or gritty instead of sparkling clean, you might be running low on salt.

Where do you put salt in the dishwasher?

The salt reservoir is usually found inside the dishwasher, below and to the left of the bottom dish rack. You should see a symbol that looks like an “S” (which stands for “salt”) made up of arrows.

Unscrew the cap and funnel in the salt until it reaches just below the lip of the reservoir, then screw the cap back on.

Is dishwasher salt the same as regular salt?

No. If you’re out of dishwasher salt, don’t fill your machine with the stuff you put on your chips. Dishwasher salt is made up of coarse granules to prevent it clogging the dishwasher salt tank, whereas table salt is finely ground.

Do I need dishwasher salt in soft water?

You need salt in every dishwasher even if you live in a soft water area. When water is softer it takes longer before you need to top up the salt. So, people living in soft water areas don’t need to change their dishwasher salt as often.

Do I use dishwasher salt if I use tablets?

All-in-one tablets clean and rinse your dishes in one cycle, with one tablet.

Like living in a soft water area, using an all-in-one tablet will help reduce the usage of your dishwasher salt, but you should still ensure your machine has some.

If you’ve noticed any issues with your dishwasher not performing at its best, it might be time to get it checked over by a qualified engineer to fix your dishwasher.

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Domestic & General Insurance PLC is an insurance undertaking, not an intermediary. We are the underwriter of the insurance and do not provide a personal recommendation or advice. Domestic & General Insurance PLC pay their sales agents periodic incentives (such as bonus payments) if they meet certain quality and sales targets. All prices include all applicable taxes (including IPT).