Breville dual boiler machines tend to be quite temperamental when it comes to descaling. People have tried following the process outlined in the manual only to end up with the infamous three beeps of death.

In my experience, only the steam boiler is affected by mineral deposits, because it runs at higher temperature, so I prefer to descale just this boiler. This process works on machines that have a drain valve at the bottom, so it won’t work for the BES900 models.

Here’s the process: (keep in mind that the video starts at the second step)

1) With a cold machine, drain the steam boiler using the valve on the right side. Don’t do it when hot! Dissolve 2 Tsp citric acid in 1 – 1.5l filtered water, pour it in the empty tank. Close the drain valve after the boiler is empty.

You should have about 500ml in the drip tray. Turn on the machine.

Listen to the pump filling up the boiler. Start a stopwatch and make sure the pump stops at around 2 minutes. If the pump doesn’t start, turn off the machine because you don’t want the heater to run when the boiler is empty. The pump should start within 10 seconds of turning on the machine. Let the machine heat up, run some steam, do NOT run any hot water or coffee.

2) Wait for an hour or until the machine is cooler but not completely cold. Drain the boiler again. Make sure about 500ml come out. You should see a bunch of mineral deposits come out. Make sure not to drain it while hot! You’re guaranteed to burn your hand if you do that. Empty and rinse the water tank. Fill the tank with fresh water.

3) Close the drain valve, turn on the machine, listen to the pump filling up the boiler for about two minutes.

Again pay attention: do NOT let the machine run if the pump doesn’t fill up the boiler. The pump should start within 10 seconds of turning on the machine. Let the machine heat up, run some steam, and then let it cool off again and repeat the last rinse (step 2).

Now your machine should be clean and ready to make coffee and steamed milk. Enjoy!