How To Descale A Breville Dual Boiler

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Even if you clean your coffee machine regularly, the mineral deposits in the water will result in the build-up of limescale on the internal components.

This can impact the taste and temperature of your coffee and can also impact its useful life.

Below, we cover the basic steps for descaling your Breville Dual Boiler coffee machine.

How often hould you descale a Breville Dual Boiler?

The frequency that your Dual Boiler needs descaling will depend on a number of factors, including:

  • How often you use the machine
  • The type of water in your area
  • Whether you use a water filter or treat it in another way

Breville recommends that you should descale your coffee machine every 60 – 90 days, depending on your water hardness.

However, most people would consider this to be excessive for a domestic coffee machine.

What you’ll need:

  • Flathead screwdriver
  • Microfibre towel
  • Spoon
  • Breville descaling solution

How to descale a Breville Dual Boiler

Step 1: Turn off your Breville Dual Boiler and let it cool for at least an hour.

Step 2: Remove the water tank

Step 3: Locate your batch code – this will be the first four digits on the sticker behind the water tank

Step 4: Check your batch code is above 1537. If not, you have an older version of the Dual Boiler so the descaling process will differ. Check out Breville’s guides for earlier models.

Step 5: Press and hold the 1 cup and power button at the same time. Then press the up button, then the menu button. The single cup button will be lit up.

Step 6: Remove the rubber plug above the drip tray then unscrew the left drain valve behind it. Water will begin to drain from the boiler into the drip tray.

Step 7: Unscrew the right drain valve (be careful of hot water). This will release water from the steam boiler.


The Breville Dual Boiler descaling process requires you to release the two drain valves on three occasions. To avoid causing damage, it’s important to unscrew these as slowly as possible due to the build-up of pressure within the machine.

Step 8: Empty the drip tray, replace it, then gently tighten up both valve screws.

Step 9: Remove the water tank and remove the filter from within the water tank.

Step 10: Fill the water tank with 1 litre of water then add your descaling solution. Mix the water with a spoon until the water is clear.

Step 11: Replace the water tank then press the one cup button to start the descaling process (takes 20min).

Step 12: When the descaling process is complete you will see a blank LCD screen.

Step 13: Unscrew the left drain valve which will release water from the coffee boiler into the drip tray.

Step 14: Unscrew the right drain valve to drain the steam boiler (be careful of hot water).

Step 15: Empty the drip tray, replace it, and then gently tighten up both valve screws.

Step 16: Remove the water tank and discard the remaining solution. Refill the water tank with 1 litre of water.

Step 17: Return the water tank and lock it in place.

Step 18: Press the 1 cup button to flush the machine (takes 20 min).

Step 19: When complete you should see a blank LCD screen.

Step 20: Unscrew the left drain valve which will release water from the coffee boiler into the drip tray.

Step 21: Unscrew the right drain valve to drain the steam boiler (be careful of hot water).

Step 22: Empty the drip tray, replace it, and then gently tighten up both valve screws.

Step 23: Reinstall the rubber drain plug.
Step 24: Remove the water tank, reinstall the filter, then refill the water tank to the max level. Reinstall the water tank.

Step 25: You can now power up your coffee machine and it’s ready to use once it reaches brewing temperature.

For a visual guide, check out the video below:

Why do you need to descale your Breville Dual Boiler?

If you don’t de-scale your coffee machine regularly, it may become clogged up with limescale. 

This will reduce its efficiency and make it prone to breaking down. Limescale build-up can also impact the taste of your coffee if you let it build up for long enough.

If limescale builds up on the heating elements of your coffee machine, you may find that it doesn’t heat water to the optimum temperature for brewing. 

This means the water may not be hot enough to extract the full flavour of your beans. You may even end up with lime scale in your cup.

What does descaling a coffee machine do?

Coffee machine descaling is the process of removing mineral deposits that build up inside the machine over time. Coffee machine descaling solutions are acidic, such as hydrochloric acid, which can corrode metal (e.g., brass and steel) components.

The descaling solution will break down the calcium carbonate and magnesium carbonate that is present in the limescale, thus extending the life of your coffee machine and keeping your coffee tasting fresh.

Can you descale a coffee machine with vinegar?

Many people use vinegar as an effective and inexpensive way to descale a coffee machine.

This method involves mixing one part white vinegar to one part water and running it through a brewing (or descaling) cycle.

Afterwards, run the machine through another full cycle with plain water until there’s no more vinegar taste.

Vinegar works as a descaler precisely because it contains acetic acid. When the acetic acid comes into contact with calcium deposits, or scale build-up, it forms something called acetate salts which causes them to break down.

However, many coffee manufacturers recommend against using vinegar.

For example, Delonghi advises against it because “vinegar contains large amounts of acetic acid which is an aggressive chemical substance that can be corrosive.”

On the Breville website, you can find recommendations for using vinegar on several of their other machines, including the Duo Temp Pro and the Barista Express.

According to a discussion on Reddit, there was once a recommendation by Breville to use vinegar for the Dual Boiler, but they no longer recommend it. There is currently nothing in the BDB manual that mentions vinegar.

While there are many people who have reported ongoing success with descaling their BDB with vinegar, keep in mind that you may run the risk of invalidating the warranty by using a non-approved descaling product.