Breville Barista Express Leaking Water? Find Where It's Coming From and Stop It

A puddle around an espresso machine sets off alarm bells, but “leaking” covers everything from a tank that’s a millimetre out of place to a perished seal deep inside. The trick is to stop guessing and find out where the water actually appears — because each location points to a different, usually cheap, fix.

Grab a dry cloth, pull a shot, and watch closely. Where the first water shows up is your diagnosis.

First, locate the leak

• Front, around the portafilter, during a shot: the group head gasket. Go to Cause 3.
• Back, near the tank: tank seating, overfill or a cracked tank. Cause 1.
• Underneath, pooling on the counter: drip tray overflow first (Cause 2), then internal seals (Cause 5).
• A little water in the drip tray after heating/shots: that’s normal purging, not a leak.

Cause 1 — Water tank (seating, overfill, or a crack)

Why it happens: The tank feeds through a valve in its base that seals on a pin in the machine. If it’s seated at a slight angle, overfilled above MAX, or the tank itself has a hairline crack, water escapes at the back.

The fix: Remove the tank, wipe the seating area and the valve, and check the tank for cracks (hold it full over a sink). Refit it with a firm, straight push until it sits flush — not tilted. Don’t fill past the MAX line.

Cause 2 — Overflowing drip tray (mistaken for a leak)

Why it happens: The Barista Express purges water into the drip tray by design. If you haven’t emptied it in a while, it overflows onto the counter and looks exactly like a leak from underneath.

The fix: Pull out the tray and empty it. The red “EMPTY ME” float pops up through the tray grate when it’s full — if you can see it, the tray is overdue. Make emptying it part of your routine.

Cause 3 — Worn group head gasket

Why it happens: The rubber gasket in the group head that the portafilter seals against hardens and shrinks with heat and age (typically after a year or two of regular use). Once it loses its squish, pressurised water sprays out around the portafilter during the shot instead of going through the coffee.

How to confirm: Lock in the portafilter — if it now sits much further round than it used to (well past the centre), the gasket is compressed and worn.

The fix: Replace the group head gasket. It’s an inexpensive part; you remove the shower screen to access it, pry out the old gasket and press the new one in. Ten minutes and the side-spray is gone.

Cause 4 — Scale-related seepage

Why it happens: Heavy scale can cause valves and seals to seat poorly and weep, and it stresses the system. If you’re in a hard-water area and overdue a descale, scale may be behind a slow seep.

The fix: Run a full descale, then fit a fresh water filter. See our descaling guide. It won’t fix a torn gasket, but it resolves scale-related weeping and protects the machine.

Cause 5 — Internal hose or O-ring

Why it happens: Inside, water travels through hoses joined with O-rings and clamps. Age, heat and scale can let one weep, so water collects under the machine (often routed into the tray, sometimes onto the counter).

How to confirm: If the tank, tray and group gasket are all ruled out and water still appears underneath during operation, it’s internal.

The fix: This means opening the machine to find and reseat or replace the weeping seal/hose. It’s doable for the confident, but it’s a job many owners hand to a technician.

Repair or replace?

Leaks are almost always a repair, and a cheap one: reseating, an empty tray, a $5–10 gasket, or a descale handle the overwhelming majority. Only a serious internal failure on an old, out-of-warranty machine would tilt toward replacement — and even then it’s usually a fixable seal. If it’s under warranty, contact Breville before opening anything.

Stop it happening again

• Empty the drip tray regularly and don’t overfill the tank.
• Replace the group gasket every 12–18 months as routine, before it sprays.
• Descale on schedule and keep a water filter fitted.