How to Safely Descale Your Breville Dual Boiler (BES920) & Oracle (BES980,BES990)
Descaling your espresso machine is a crucial maintenance step to ensure its longevity and the quality of your coffee. However, for owners of certain Breville Dual Boiler models, particularly those manufactured before mid-2022, the descaling process can pose a significant risk: blowing the thermal fuse. This can lead to a costly repair, often referred to as the "three beeps of death." This guide will walk you through a safe and effective descaling method that mitigates this risk, keeping your machine in top condition.
Understanding the Risk: The 'Three Beeps of Death'
Many Breville Dual Boiler machines, especially those produced before mid-2022, have a design characteristic that makes them vulnerable during the descaling process. The primary danger arises when the boiler attempts to heat while empty. If this occurs, the thermal fuse can blow, resulting in the machine emitting three distinct beeps – a clear indicator of a significant and often expensive repair. This issue is particularly prevalent during descaling if the machine is allowed to run dry while heating elements are active.
You can determine your machine's manufacturing date by looking at the first four digits of its serial number. These digits represent the year and week of manufacture (YYWW format). For example, '2145' would mean the 45th week of 2021:
If it's dated 2022, then you can determine if your machine is affected with this issue by the type of boiler you have. It will either have version 2 or 3. Version 3 uses different probes that aren't affected by this problem.
The Safe Descaling Method: A Step-by-Step Guide
To prevent the dreaded 'three beeps of death' and ensure a safe descaling process, follow these steps carefully:
Step 1: Preparation is Key
Before you begin, ensure your machine is completely powered off and unplugged from the wall socket. Next, carefully remove the top lid of your Breville Dual Boiler. This will give you access to the internal components. Locate the steam boiler water sensors and disconnect the blue wire connected to the middle one. This crucial step prevents the boiler from heating up while it's empty during the descaling process:
Step 2: The Descaling Process
With the heat sensor disconnected, you can now safely proceed with the descaling. Access the advanced menu on your machine or wherever the descale option is and start the 'descale' process. This will initiate the draining of both boilers. Once drained, fill your machine's water tank with a descaling solution mixed with hot water. This is to compensate for the lack of heat from the boiler as the solution works best when warm. Allow the machine to fill the boilers with the solution. Let the solution sit in the boilers for approximately 20 minutes to break down mineral deposits. After 20 minutes, drain the solution from the machine. If you can't drain any water out from the right-side port then see step 3 below.
Step 3: Troubleshooting a Blocked Drain Valve
Occasionally, stubborn scale buildup can block the drain valve, preventing the solution from draining completely. If this happens, do not force it. Instead, allow the descaling solution to sit in the machine overnight; the solution will continue to dissolve the scale, often clearing the blockage by morning. As an alternative, you can carefully use a thin, flexible wire down through the anti-vac valve to gently clear the blockage, but exercise extreme caution to avoid damaging any internal components.
Here is a photo of the internals so you can get an idea of just how small that drain hole is:
Step 5: Rinsing and Finishing
Once the descaling solution has been drained, continue through the rest of the rinsing process with fresh, clean water. Since the boiler's heat sensor is disconnected, you can bypass the usual rinse cycle countdowns, making this step quicker and more efficient.
⚠️ After rinsing, and completing the descale cycle, make double sure your boiler has filled up again. You should see the water levels dropping when the steam boiler is filling up. Once you are confident this is the case, reattach the blue wire to the steam boiler sensor and replace the top lid to finish.
Conclusion
By following this safe descaling method, you can confidently maintain your Breville Dual Boiler without the fear of a costly thermal fuse repair. This process, while requiring a bit more hands-on effort, is a small price to pay for the longevity and performance of your beloved machine.
This blog post was based on the YouTube video "How to Safely Descale Your Breville Dual Boiler (BES920) & Oracle (BES980,BES990)" by BrevTech. You can watch the original video here.