How often should you empty a dehumidifier? Experts explain how to keep yours working efficiently

How often you empty your dehumidifier can affect your machine’s performance, according to experts.

A dehumidifier acts to remove moisture from your room, improving air quality, drying clothes and combating issues with damp, mould and condensation. If you’ve invested in one of the best dehumidifiers, you’ll already be well-versed in how good they are. But even with a top-of-the-range model, you need to ensure your machine is well looked after, to avoid making any dehumidifier mistakes.

One common mistake to make is neglecting to empty your dehumidifier the correct amount. When it comes to how often you should empty your dehumidifier, there is no clear-cut answer. All you have to do is bear in mind the humidity of your room compared to the capacity of your dehumidifier.

How often should you empty a dehumidifier?

There is a common misconception that the more you empty your dehumidifier, the more efficient your machine will be.

‘The frequency of emptying your dehumidifier depends on the humidity levels in your home, the size of the water tank, and how much moisture the dehumidifier is pulling out of the air,’ says Chris Michael, managing director of Meaco. ‘If your machine is filling up quickly, it’s a sign that it’s working effectively in removing moisture, but that doesn’t mean a less frequent need to empty it indicates poor performance. It may simply mean that your room’s humidity level is stabilising, or the dehumidifier is sized appropriately for the space.’

When it comes to emptying your dehumidifier there is no hard and fast rule either - it entirely depends on how much liquid your dehumidifier can hold. Some dehumidifiers can hold up to 12 litres of water while others hold under a litre. Choosing the right size dehumidifier, all depends on how humid your home is - if you're looking to use one across your whole house instead of one room, a larger dehumidifier is needed.

‘How often you need to empty it will depend on how humid your space is and the size of your dehumidifier’s tank. For most people, it could range from once a day to every few days. If you’re in a particularly damp environment or are using a dehumidifier for the first time, you may find yourself emptying it more frequently during the first few days when the machine is working its hardest to bring down the humidity,’ says Chris.

Most dehumidifiers will let you know when they need emptying. Some automatically shut off while others have an indicator light or even have an audible noise when the cycle is done.

Why you need to empty your dehumidifier

If you don’t empty your dehumidifier, leaving the water in the tank, this is where problems can occur.

‘It’s a bad idea to not empty your dehumidifier as this will, quite simply, stop your appliance from working. If the tank is full, the machine cannot collect more water which means it won’t be reducing humidity levels effectively,’ says Joshua Warren, dehumidifier expert at AO.com

‘You’re also faced with the prospect of stagnant water in your tank from causing unpleasant odours. Simply be vigilant in future and empty your dehumidifier whenever you have the chance!

‘Leaving water in your dehumidifier for prolonged periods can lead to some issues. Stagnant water leaves a musky smell, and, in some cases, this water can corrode your dehumidifier’s internals – which may shorten the lifespan of your appliance.

‘To avoid these problems, simply empty its tank after every use and keep your dehumidifier running healthily.’

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When you empty your machine, use the opportunity to clean your dehumidifier, to help it to continue to run efficiently.

While there are no hard and fast rules for exactly how often you should empty your dehumidifier, it’s important to pay attention to your machine, emptying it every time the tank is full.