Breville Infuser (BES840) Descaling Guide

Two Books, Two Ways to Descale

Breville has printed two different descaling methods for the Infuser (BES840). The US book uses a manual vinegar pour. The newer book has a Descale mode with Breville's powder. The light on your machine tells you which book you have: CLEAN ME on the US machine, DESCALE/CLEAN on the newer one.

• US book (BES840XL): no descale mode. You run a 50/50 white vinegar and water mix through by hand. The light on this machine is CLEAN ME, and it asks for a cleaning cycle, not a descale.
• Newer book (ANZ K21): a Descale mode entered with 2 CUP + POWER, using Breville descaling powder. Its DESCALE/CLEAN light is solid when descaling is due and flashing when a cleaning cycle is due.

Both books say scale reduces "the brewing flow, brewing temperature, power of the machine, and taste of the espresso." Both warn: "The water tank should never be removed or completely emptied during decalcifying."

---

What You'll Need

• A large container for under the group head and steam wand
• US method: white vinegar and cold tap water
• K21 method: one sachet of Breville descaling powder and 1 litre of water
• About 30 minutes

Take the water filter out first. The K21 book says to remove it before adding descaler.

---

Which Light Is On?

---

US Method: Manual Vinegar Pour

1. Remove the portafilter.
2. Pour a 50/50 mix of white vinegar and cold tap water into the tank.
3. Put a large container under the group head and steam wand.
4. When the machine is hot and all the button lights are on, hold 1 CUP for a manual pour. Let go when half the mix has run through.
5. Turn the dial to HOT WATER for about 30 seconds, then back to STANDBY.
6. Turn the dial to STEAM for about 2 minutes, then back to STANDBY.
7. Hold 1 CUP again until the tank is empty and nothing more runs through.
8. In hard water, repeat the cycle.
9. Rinse: wash the tank, fill it with fresh cold water, and repeat the steps.

The US book recommends this every month, and before you leave the machine unused, for example before a holiday.

---

K21 Method: Descale Mode

1. Dissolve one sachet of Breville descaling powder in 1 litre of water and fill the tank.
2. Hold 2 CUP, then hold POWER as well to enter Descale mode. POWER flashes while it heats.
3. It's ready when POWER, 1 CUP, DESCALE/CLEAN and HOT WATER/STEAM are all lit.
4. Press 1 CUP to descale the coffee side, which takes about 25 seconds.
5. Turn the dial right for steam (about 13 seconds), then left for hot water (about 8 seconds).
6. About half the solution (0.5 L) will be left. Repeat steps 4-5 to use it up.
7. Rinse: wash the tank, refill to 2 litres with fresh cold water, and repeat steps 4-5.
8. Press POWER to exit. The lights go off.

If nothing happens for 5 minutes, the machine turns itself off. Start again from step 2.

---

The Cleaning Cycle (Not a Descale)

When CLEAN ME (US) or a flashing DESCALE/CLEAN (K21) shows, the machine wants a back-flush:

1. Put the 1 CUP basket in the portafilter, then the cleaning disc, then 1 cleaning tablet.
2. Lock it in. Fill the tank and empty the drip tray.
3. Turn the machine off.
4. Hold 1 CUP + 2 CUP + POWER: 10 seconds in the US book, 3 seconds in the K21 book.
5. It runs about 5 minutes and beeps 3 times at the end (US book).
6. If the tablet hasn't dissolved, run it again.

---

If the Light Won't Go Off

• CLEAN ME still on after a descale? It's asking for the cleaning cycle above, not a descale.
• DESCALE/CLEAN flashing after a descale? Same answer: run the cleaning cycle.
• DESCALE/CLEAN still solid? Repeat the K21 method, letting each part run to the end.

Our Breville descale light guide covers other models' lights.

---

Refit the Water Filter Afterwards

The filter comes out before descaling. When you put it (or a new one) back, follow the book's steps:

1. Soak the filter in a cup of water for 5 minutes, then rinse it under cold running water.
2. Rinse the filter holder's stainless steel mesh with cold water.
3. Fit the filter into the two halves of the holder.
4. Set the date dial 2 months ahead.
5. Push the holder down onto the adapter inside the tank until it locks, then lock the tank into the machine.

---

Keep Scale Down

• Change the water filter every 2 months, and sooner in hard water. The US book says this "will reduce the need to decalcify".
• Remove the filter if you use filtered or bottled water.
• Don't use demineralised or distilled water. The book says not to.

---

FAQ

Can I use vinegar to descale my Infuser?

The US book uses a 50/50 white vinegar and water mix. The K21 book uses Breville descaling powder, 1 sachet per litre. Use the method from the book for your machine.

How often should I descale the BES840?

The US book says every month, and before leaving the machine unused for a while. The K21 book says to descale when the DESCALE/CLEAN light is solid.

Is CLEAN ME the descale light?

No. On the US machine, CLEAN ME asks for a cleaning (back-flush) cycle with a tablet. The book says it is "separate from decalcifying".

How do I know my Infuser needs descaling?

The book links scale to low flow, lower temperature, weak steam and poorer taste. On a K21 machine the DESCALE/CLEAN light also comes on solid.

---

Related Breville Guides

• Breville Infuser Not Working?: the full troubleshooting table
• Breville Infuser Leaking Water?: the seal, tank and auto purge
• Breville Descale Light Won't Turn Off?: other Breville models

Sources: Breville the Infuser BES840XL Instruction Book (USC) and BES840 Instruction Book (ANZ K21).