How to Descale Breville Barista Express: BES870 Steps

Solid CLEAN/DESCALE light? Breville's BES870 manual steps for descale mode, all three water paths and the rinse, plus where guides and manuals disagree.

By Maksud · Published Oct 3, 2026

To descale a Breville Barista Express, wait for a solid CLEAN/DESCALE light; a flashing one means the backflush cleaning cycle instead. Per Breville’s BES870 manual (p.25), dissolve one Breville descaling sachet in 1 L (34 fl oz) of water in the tank. Hold 2 CUP, then POWER, to enter descale mode. Run 1 CUP, then steam, then hot water, and repeat until the tank is empty. Rinse with a full 2 L tank.

Flashing vs solid: what the Barista Express CLEAN/DESCALE light means

The Barista Express has one light for two different jobs. The BES870 manual (p.10) says it “illuminates when a cleaning cycle or descaling is required”, and the pattern tells you which:

• Flashing: run the cleaning cycle. The manual (p.24) calls it “a back-flushing cycle” that is “separate from descaling”. It uses a cleaning tablet; Daniel Norris and BetterCoffeeDays describe it as clearing coffee oils, not minerals.
• Solid: descale (p.25). This removes mineral scale, which the manual says reduces “brewing flow, brewing temperature, power of the machine, and taste”.

BetterCoffeeDays says most people assume the reverse, treating the blinking light as the more serious alert and reaching for descaler. Daniel Norris says the shared light trips people up.

EspressoMachineLab, writing about Breville machines in general rather than this model, says the cleaning light comes on after “roughly 200 extractions”. Neither Breville manual we read says how the light is triggered, so treat that figure as unconfirmed.

Barista Express cleaning cycle vs descale: side-by-side

Both jobs use the same light and the same POWER button, so they are easy to mix up. Cells marked manufacturer spec come from Breville’s BES870 manual; the one that doesn’t is credited to its source.

The cleaning-cycle hold time is not consistent across sources. The US BES870 manual says about 10 seconds. Breville’s BES875 manual for Australia and New Zealand (p.24) says 3 seconds in both its text and its diagram (“hold together 3 sec”). BetterCoffeeDays also says 3 seconds. The 10 s figure is the US manual for this model.

What you need before you start

• One Breville descaling powder sachet. That is what the BES870 manual names. If your market supplies a different approved product, CoffeeFixGuide says to follow its dilution label and the manual for your exact model.
• A large heat-safe container under the group head and steam wand to catch the solution. The manual’s descale steps don’t mention one; Daniel Norris and CoffeeFixGuide both call for it.
• Fresh cold water for the 2 L (68 fl oz) rinse.
• An empty drip tray, per Daniel Norris and CoffeeFixGuide.
• The steam dial at STANDBY. The machine won’t heat otherwise (manual p.29).
• Gloves and care around your eyes. Breville’s safety data sheet for its Descaler (BES007) lists malic acid (30-60%), sulfamic acid (10-30%) and citric acid (1-10%). It is labelled as causing skin irritation and serious eye irritation, and advises protective gloves and eye protection.

BES870XL descale mode: step by step

These steps follow page 25 of Breville’s BES870 manual, with third-party additions credited where they appear:

1. Confirm the CLEAN/DESCALE light is solid, not flashing.
2. Dissolve one descaling sachet in 1 L (34 fl oz) of water and fill the tank. Seat the tank fully.
3. Press and hold 2 CUP, then press and hold POWER. CoffeeFixGuide says to do this with the machine off and the dial at STANDBY. POWER flashes while the machine heats. It is ready when POWER, 1 CUP, CLEAN/DESCALE and HOT WATER/STEAM are all lit solid.
4. Press 1 CUP to send solution through the coffee circuit. It runs for about 25 seconds; press 1 CUP again to stop early.
5. Turn the dial right to steam. Solution runs through the wand for about 13 seconds.
6. Turn the dial left to hot water. It runs for about 8 seconds; turn to STANDBY to stop early. About 0.5 L (17 fl oz) should be left in the tank.
7. Repeat steps 4 to 6 until the tank is empty.
8. Remove and rinse the tank, refill it to MAX, 2 L (68 fl oz), with fresh cold water, and repeat steps 4 to 6.
9. Press POWER to exit descale mode. The LEDs go off.

In descale mode the machine turns itself off after 5 minutes with no action. If that happens, start again from step 3.

Sources put the whole job at very different lengths. TechGearLab’s testers, in its espresso machine roundup, report it took less than 10 minutes. CoffeeFixGuide says 10 to 15, The Green Pods 15 to 20 plus the rinse, Daniel Norris about 30, and BetterCoffeeDays 30 to 45 minutes. The manual’s own figures come to about 46 seconds of pump time per pass. The rest is heat-up, refilling and emptying the container.

Water filter: take it out or leave it in? Where sources disagree

Breville’s own manuals don’t agree. The US BES870 manual’s descale steps never mention the filter. The only filter removal it describes (p.24) is when you use filtered or bottled water.

Breville’s BES875 manual for Australia and New Zealand (p.24) is explicit: “Ensure that the water filter is removed from the water tank before adding the descaling powder.” Tom’s Guide, Daniel Norris, BetterCoffeeDays and The Green Pods all say to remove it too. The Green Pods says the filter absorbs the descaler’s acidity, but cites nothing for that.

The evidence leans toward taking the filter out, while the US manual we downloaded on Oct 3, 2026 is silent either way.

The manual’s own contradiction about removing the tank

The BES870 manual warns that the tank “should never be removed or completely emptied during descaling”. Then step 8 tells you to remove and rinse it before the rinse pass.

CoffeeFixGuide and Daniel Norris read it this way: don’t pull the tank while the pump is running, and only take it out between the solution pass and the rinse pass. That is the only reading that fits both lines. Keep the machine in descale mode while you refill, and get back to it within 5 minutes so it doesn’t switch itself off.

If descale mode won’t start or the light stays on

• Steam dial not at STANDBY. The manual’s troubleshooting (p.29) says the machine won’t heat up otherwise.
• Tank not fully seated. The manual’s troubleshooting (p.29) lists a tank that is not fully inserted and locked as a cause of no water flow; push it down until it locks.
• Wrong order. Hold 2 CUP first, then add POWER, per CoffeeFixGuide.
• Wrong combination. Don’t use the three-button 1 CUP + 2 CUP + POWER combo; that starts the cleaning cycle, as BetterCoffeeDays and CoffeeFixGuide point out.
• Machine timed out. After 5 minutes idle it turns off; restart from step 3.
• Light still solid afterwards. The manual’s step 8 runs the rinse through all three circuits (coffee, steam, hot water) and step 9 exits with POWER, so check that neither was skipped.
• Different version. CoffeeFixGuide notes that button behaviour can differ across Barista Express versions, so check the manual that came with your unit.
• Pump loud, no water. CoffeeFixGuide says to stop if the pump gets unusually loud or an outlet gives no water, and to contact Breville support or a qualified technician if the pump keeps running without moving water. The BES870 manual (p.29-30) lists “Machine needs to be descaled” as a cause when no water flows or espresso only drips.

BetterCoffeeDays suggests unplugging for about 10 minutes if the light won’t clear, and a PROGRAM-button factory reset as a last resort that also wipes saved shot volumes. Neither Breville manual we read lists either fix for the descale light.

How often to descale a Barista Express

Breville gives no fixed interval in the BES870 manual: descale when the light is solid. The manual (p.24) says replacing the water filter every two months reduces the need to descale, and to replace it more often in hard water.

Other sources give rough schedules. TechGearLab says the machine needs descaling and a filter change “every couple of months with regular use”, and The Green Pods says every 2 to 3 months. The manual (p.3, p.12) recommends cold filtered water and advises against demineralised or distilled water.

For how water hardness affects that interval, see our guide to descaling any espresso machine.

Vinegar on a Barista Express?

Breville’s BES870 manual calls only for Breville descaling powder, and its safety section (p.3) says “do not use any other liquid” in the tank. Daniel Norris, BetterCoffeeDays and The Green Pods all advise against vinegar because of the smell it can leave; The Green Pods adds taste.

The Green Pods also claims frequent vinegar use can damage metal parts and void the warranty. BetterCoffeeDays is less sure: it says vinegar “probably” won’t void a claim but calls it a grey area. Neither Breville manual we read mentions vinegar or the warranty, so treat the warranty point as unconfirmed. For the general case on drip machines, see vinegar vs descaler.

Related Barista Express and espresso guides

• How to descale an espresso machine
• Breville Barista Express review, including how much upkeep it asks for
• Best espresso machines
• Breville Bambino Plus flashing lights: the Bambino Plus uses a different descale button combo
• How we research