My Espresso Machine Won't Build Pressure — Common Causes

An espresso machine that won't build pressure is, in the large majority of cases, dealing with a coffee puck that offers too little resistance for the pump to push against — not a broken pump. Pressure is a product of resistance meeting flow, and if the grind is too coarse or the dose too light, water sails through with barely any resistance regardless of how healthy the pump is.

Work through these five causes in order — they're listed from most to least common, and checking them in this sequence saves you from tearing into the machine for what's usually a grind or gasket problem.

Your grind is too coarse

A grind that's too coarse creates large gaps between particles, and water finds an easy path through with minimal resistance. Without resistance, the pump has nothing to push against, and the pressure gauge — if your machine has one — barely moves off zero.

Fix: Tighten the grind noticeably, several clicks at a time, and watch the shot: if it starts flowing within a couple of seconds and never really slows down, the grind is still too open. You should see some initial resistance before flow begins.

Your dose is too low

Similar mechanism, different variable — a light dose means a shallow, loosely packed puck with less total surface area and resistance to push against, even at a reasonably fine grind.

Fix: Weigh your dose against the basket's rated capacity, typically 18g for a double, and don't underfill "to be safe." A puck that's too shallow can't build pressure no matter how fine you grind it.

Your group gasket is worn or misseated

The gasket seals the portafilter against the group head so pressure builds inside the puck rather than leaking out around the basket. A hardened, cracked, or improperly seated gasket lets water bypass the coffee entirely, and you'll often hear a hissing or spraying sound at the portafilter handle during a shot as a giveaway.

Fix: Inspect the gasket for visible cracking, flattening, or a shiny, hardened texture — signs it's lost its seal. Gaskets are a wear item on nearly every semi-automatic machine and typically need replacement every one to two years of regular use, sooner with heavy daily use.

Your shower screen is clogged

The shower screen distributes water evenly across the puck. Mineral scale or old coffee residue can partially block it over time, which sounds like it would increase pressure but often does the opposite — it channels water unevenly, letting it find a low-resistance path through the puck instead of extracting evenly under proper pressure.

Fix: Remove and clean the shower screen (or run a proper backflush cycle with a blind basket, if your machine supports it) especially if you're on hard water without a filter. A visibly stained or crusted screen is a clear sign it's overdue.

Your pump is failing (the last-resort explanation)

If grind, dose, gasket, and shower screen all check out and pressure is still absent, a failing pump — worn seals, a bad check valve, or an electrical issue — is the remaining explanation. This is real, but it's genuinely uncommon relative to the coffee-side and gasket-side causes above, and it's worth ruling out everything else first since pump diagnosis usually means opening the machine.

Fix: If you suspect the pump, listen for it running when the machine is switched on — a pump that's silent or making a very different sound than usual is a stronger signal than pressure alone. At that point, a qualified repair tech or the manufacturer's service line is the right next step rather than guessing further.

The practical order to check things

Grind and dose first, since they're free to test and explain most no-pressure complaints. Gasket and shower screen next, since both are cheap, visible, and common failure points on a machine that's a couple of years old. The pump comes last — not because it never fails, but because it almost never fails before everything upstream of it does.