Breville Barista Pro Not Working? 6 Fixes (BES878)

Read the Barista Pro's Screen First

A Breville Barista Pro (BES878) that stops working usually says why on its LCD. FILL TANK means water, LOCK HOPPER means the bean hopper isn't locked in place, and FLUSH or DESCALE is a maintenance alert. Er is the one message Breville says to take to Consumer Support. With a blank screen mid-use, the thermal cut-out has probably tripped.

The Pro heats with a ThermoJet under PID control, which Breville says reaches extraction temperature in about 3 seconds. So it isn't slow to heat, and waiting rarely helps. When water won't come through, the cause is almost always the tank, the grind, or a blocked basket. Those are the first three fixes.

---

Try This First

• Read the LCD. Note any word or icon that's lit: FILL TANK, LOCK HOPPER, FLUSH, DESCALE or Er.
• Lift the tank and push it back down until it locks, with water above MIN.
• Turn the hopper dial to make sure the hopper is locked.
• Press 1 CUP with no portafilter in. If water flows from the group head, the machine is fine and the problem is in the basket.
• If it went dark mid-use, switch off, unplug and leave it for 30-60 minutes (Fix 6).

---

What's It Doing?

---

Fix 1: Fill and Lock the Water Tank (Works About 25% of the Time)

Breville's troubleshooting table lists "water doesn't come through (the machine makes loud noise)" with one cause: the tank is empty or below MIN. A tank that isn't pushed fully down is the other cause of no water from the group head. The pump runs loud because it's pulling air.

Signs it's this one:

• A loud pumping noise with almost no water
• FILL TANK on the LCD
• It started after refilling or moving the machine

1. Lift the tank out by its handle.
2. Check the water filter is clicked into its holder in the tank.
3. Fill with fresh, cold tap water to just below MAX.
4. Set the tank back and press it down until it's seated and locked.
5. Press 1 CUP with no portafilter to check water flows.

Time: 2 minutes
Cost: Free
Success Rate: About 25%
Difficulty: Easy

Breville says not to use highly filtered, demineralized or distilled water in this machine. Replace the water daily.

---

Fix 2: Coarsen the Grind and Trim the Dose (Works About 25% of the Time)

When espresso only drips, Breville's book treats it as over-extraction, not a breakdown: the coffee is too fine, there's too much of it, or it's tamped too hard, so water can't push through. The Barista Pro's guide is that flow should start after about 8-12 seconds and look like warm honey. No flow by about 15 seconds means the grind is too fine.

Signs it's this one:

• Drips, or nothing, after the pre-infusion stage
• Dark, spotty crema and a bitter, burnt taste
• It began after a new bag of beans or a grind change

1. Turn the GRIND SIZE selector a few numbers coarser. There are 30 settings, and the default is 15.
2. Check the basket: about 8-10 g for the 1 CUP basket and 19-22 g for the 2 CUP.
3. If the dose is high, turn the GRIND AMOUNT dial anti-clockwise to shorten the grind time. The defaults are 9.5 s (1 cup) and 13 s (2 cup).
4. Tamp at about 15-20 kg (33-44 lb). The top of the tamper cap should sit level with the basket rim after tamping.
5. Trim the puck with the Razor tool.
6. Pull a shot and adjust one thing at a time.

Time: 10-20 minutes
Cost: Free
Success Rate: About 25%
Difficulty: Easy

Pre-ground coffee goes in the Dual Wall baskets, not the Single Wall ones. Breville's no-crema row lists this mistake too.

---

Fix 3: Unblock the Filter Basket (Works About 15% of the Time)

If water runs freely from the group head with the portafilter out, but stops when it's in, the basket is the restriction. Fine coffee and oils clog its holes over time. Breville lists "the filter basket may be blocked" under both "drips" and "no crema".

Signs it's this one:

• Good flow from the empty group head, little through the basket
• Grind and dose haven't changed

1. Hold the empty basket up to the light and look for closed holes.
2. Clear them with the pin on the end of the cleaning tool.
3. Still blocked? Dissolve a cleaning tablet in hot water and soak the basket and portafilter for about 20 minutes. Rinse well.
4. Rinse the basket and portafilter under hot water after every use from now on.

Time: 5-25 minutes
Cost: Free (a tablet from the box)
Success Rate: About 15%
Difficulty: Easy

Breville says not to put any of the parts in the dishwasher.

---

Fix 4: Lock the Hopper and Clear the Grinder (Works About 15% of the Time)

The LCD has a LOCK HOPPER icon, and the hopper has to be turned and locked onto the grinder before it grinds properly. Past that, Breville's grinder rows are: no beans, a blocked grinder chamber or chute, or moisture in the chamber, often after washing parts.

Signs it's this one:

• LOCK HOPPER on the LCD
• The motor runs but nothing comes out
• A loud racket while grinding (a foreign object)

1. Unlock the hopper, lift it off, check for debris, refit it and turn the dial to lock it.
2. Fill it with fresh beans.
3. Nothing comes out: run the grinder empty, remove the top burr, and brush the burrs and chute.
4. Still blocked: follow the book's advanced cleaning. Set GRIND SIZE to 1, loosen the nut clockwise with a 10 mm socket, set GRIND SIZE to 30, then remove the top burr, lower burr and grind fan. Clear the chute with the brush or a pipe cleaner, rebuild, and tighten the nut anti-clockwise. Set GRIND SIZE back to 15.
5. Wet chamber: let the burrs dry completely. Breville allows a hair dryer to blow air into the chamber.

⚠️ Safety: switch off and unplug before taking the burrs out. Breville warns the burrs are "extremely sharp".

Time: 5-30 minutes
Cost: Free
Tools: Cleaning brush; 10 mm socket for advanced cleaning
Success Rate: About 15%
Difficulty: Moderate

Full grinder steps are in our Breville grinder guide.

---

Fix 5: Run FLUSH or DESCALE When the Screen Asks (Works About 10% of the Time)

Scale is a listed cause of no water from the group head, drips, and no steam. Breville says hard-water scale reduces "brewing flow, brewing temperature, power of the machine, and the taste of the espresso". FLUSH is the separate cleaning cycle.

FLUSH (cleaning):

1. Put the cleaning disc in the basket and a cleaning tablet on top.
2. Lock in the portafilter, empty the drip tray, and fill the tank to MAX.
3. Press MENU, turn the GRIND AMOUNT dial to FLUSH, press it, then press 1 CUP.
4. When it beeps back to READY, check the tablet has gone; repeat if not.

DESCALE:

1. Empty the drip tray. Take the water filter out of the tank.
2. Fill to the DESCALE line and add descaler.
3. Press MENU, select DESCALE, then press 1 CUP.
4. Turn the steam dial to HOT WATER and to STEAM when the LCD tells you. There are three stages, and it beeps after each.
5. Refill to MAX and press 1 CUP for the three-stage rinse.

Time: About 30-40 minutes
Cost: Breville descaler; cleaning tablets
Success Rate: About 10%
Difficulty: Easy

If the alert won't clear, see our Breville descale light guide.

---

Fix 6: Let the Thermal Cut-Out Reset (Works About 5% of the Time)

Breville's answer to "machine is on but ceases to operate" is a safety thermal cut-out, triggered by the pump or grinder overheating. Long grinding sessions or back-to-back shots can trip it.

1. Press POWER to switch off, then unplug it.
2. Let it cool for about 30-60 minutes.
3. Plug in, switch on, and try again.
4. If it happens again, call Breville Support.

Time: 30-60 minutes
Cost: Free
Success Rate: About 5%
Difficulty: Easy

Two things that aren't faults: the Pro switches itself off after 30 minutes unused, and hot water stops on its own after 60 seconds, though you still turn the dial back by hand.

---

When DIY Won't Work

Contact Breville if:

• Er shows on the LCD. The book's Error Mode section says to contact Breville Consumer Support.
• The thermal cut-out keeps tripping after cooling
• Water won't flow from the empty group head with a full, locked tank and a recent descale
• You see water under the machine with the tank locked and the drip tray in place

Breville Consumer Support: 1-866-BREVILLE (1-866-273-8455) in the U.S., 1-855-683-3535 in Canada. Don't open the housing. The book's only owner repairs are the cleaning and grinder steps above.

---

Keep the Barista Pro Working

• Change the water filter every 2 months, more often in hard water. Breville says that reduces the need to descale.
• Purge the group head before each shot: press 1 CUP briefly with no portafilter to stabilize temperature.
• Run FLUSH and DESCALE when the LCD asks, not later.
• Wipe the basket rim before locking in, so the portafilter seals.
• Keep washing water out of the grinder. Dry the burrs fully before refitting.

---

FAQ

Does the Barista Pro have a factory reset?

It has RESET DEFAULTS in the menu. Press MENU, turn the GRIND AMOUNT dial to RESET DEFAULTS and select it. The machine beeps and restores the grind amount, filter size, shot temperature and the 1 CUP and 2 CUP shot settings. It doesn't fix hardware problems, but it does undo settings that have drifted.

Why does my new Barista Pro show FLUSH?

That's the first use cycle. The first time you press POWER, the machine beeps, shows FLUSH and lights the 1 CUP button. Press 1 CUP and let the countdown finish. Breville says this rinses the machine and primes the heating system, and it goes to READY afterward.

Does the Barista Pro have a pressure gauge?

No. Breville's component list has no gauge. The LCD's shot clock counts up from the start of pre-infusion, so use flow-start time instead: about 8-12 seconds is right. Under about 6 seconds is under-extracted; nothing flowing by about 15 seconds is too fine.

Why is my Barista Pro espresso not hot enough?

Breville's first answers are a cold cup and a cold portafilter. Rinse both under the hot water outlet and dry the portafilter. After that, raise the temperature under MENU → SHOT TEMP. Our Barista Pro not heating guide covers it in full.

---

Related Breville Guides

• Barista Pro Not Heating?: pre-heating and SHOT TEMP on the BES878
• Breville Grinder Not Working?: hopper lock, chute and burr cleaning across models
• Breville Won't Brew Coffee?: no flow from the group head, any model
• Breville Descale Light Won't Turn Off?: FLUSH vs DESCALE, by model
• Barista Express vs Barista Pro: if you're weighing a replacement

Sources: Breville Barista Pro BES878 Instruction Book.