Espresso Machine Troubleshooting & Maintenance Guide

✓ Last updated 14 July 2026 · 11 min read

Your machine won't turn on. It's leaking. There's no pressure, or no steam, or it's making a noise it never used to make. This guide walks through the faults we see most often in our service workshop — what causes them, what you can safely fix yourself, and the point at which you should stop and call a technician.

1. Check These Four Things First

Before you assume the worst, rule out the simple causes. Modern machines have safety interlocks that will refuse to run if something isn't seated properly — and that reads exactly like a breakdown.

• Is the water tank full and properly seated? Most machines won't pump if the tank is low or fractionally out of position. Push it firmly until it clicks.
• Is the drip tray pushed all the way in? Many machines have a sensor here and will lock out if it isn't home.
• Is the power cord secure at both ends? At the wall and at the machine.
• Is the machine actually up to temperature? Most need 15–25 minutes from cold to reach a stable brew temperature — and longer for the group head to warm through. A machine that's "not hot enough" is often just not warmed up.

If one of those brings the machine back, you've saved yourself a service call. If it's running but performing badly, keep reading.

2. The Six Most Common Faults

3. Backflushing — The Fix for Most Problems

If your machine has a three-way solenoid valve (most semi-automatic and prosumer machines do), backflushing is the single most valuable thing you can do for it.

Coffee oils build up inside the group head and the solenoid, where you can't see them. They go rancid. They taste harsh and stale, and they gradually restrict flow. Backflushing forces water and detergent backwards through those passages and pushes the residue out.

How to backflush

1. Fit a blind basket (a filter basket with no holes) into your portafilter. Most machines ship with one; if yours didn't, they're inexpensive.
2. Add a small measure of espresso machine detergent — follow the dose on the packet. Don't overdo it.
3. Lock the portafilter into the group head as you would for a shot.
4. Run the pump for around 10 seconds, then stop. Water has nowhere to go, so pressure builds and then discharges backwards through the solenoid when you stop. Repeat 5 times.
5. Remove the portafilter, rinse the blind basket thoroughly, and repeat the whole cycle 5 times with water only to flush the detergent out.
6. Pull a shot and discard it. Any residual detergent taste will be gone.

Browse espresso machine cleaning products, including detergents and blind baskets.

4. Descaling — When Flow and Heat Drop Off

Every time water is heated, dissolved minerals — mostly calcium and magnesium — come out of solution and deposit inside the machine. That's limescale. It builds inside the boiler, on the heating element, and in the narrow water lines.

Two things happen as it accumulates:

• Flow drops. The passages narrow, so the pump has to work harder to push water through and the flow becomes weak or sputtering.
• Heat drops. Scale is an insulator. It coats the element and blocks heat from transferring into the water, so shots run cool and steam gets weak.

Descaling is not the same as backflushing. Backflushing removes coffee oils. Descaling removes mineral scale. You need to do both — they solve different problems.

How often?

It depends entirely on your water. Hard water means more frequent descaling. As a rough guide, every 2–3 months in a hard-water area and every 4–6 months in a soft-water area. If you notice flow or heat dropping off, descale regardless of the schedule.

5. Replacing a Group Head Gasket

The group head gasket is a rubber ring that sits behind the shower screen and seals against the rim of the portafilter. It's the part taking the full force of every shot, and it is a consumable — it will wear out. That's not a fault, it's expected.

Signs it needs replacing

• Water leaks or hisses out around the edge of the portafilter during a shot.
• The portafilter handle has gradually crept further and further to the right to lock in — the gasket has compressed and hardened.
• Remove it and look at it: a worn gasket is flattened, cracked and rigid. A new one is soft and springy.

How to replace it

1. Unplug the machine and let it cool completely. The group head holds heat for a long time.
2. Remove the shower screen — usually a single central screw.
3. Prise the old gasket out with a small screwdriver or pick. It will likely be stuck fast. Take your time and don't gouge the seat.
4. Clean the groove thoroughly. Old coffee residue in the seat will stop the new gasket seating flat.
5. Press the new gasket in evenly all the way round. Make sure it's fully home and flat.
6. Refit the shower screen, plug in, and test. The portafilter should lock in snugly and the leak should be gone.

6. Understanding "No Pressure"

This is the one people get wrong most often, so it's worth being precise.

Your pump doesn't create pressure. It creates flow. The pressure you see on the gauge is resistance — it's the coffee puck pushing back against the water trying to get through it.

So if your gauge sits low and the shot gushes out in ten seconds, the pump is almost certainly fine. There's simply nothing there to push against. The coffee is too coarse, or there isn't enough of it, or the puck has channelled and the water has found a free route through.

This means "no pressure" is usually a coffee problem, not a machine problem — and it's covered properly in our espresso extraction guide. Check grind, dose and tamp before you suspect the hardware.

When it genuinely is the machine

• The gauge reads low even with a blind basket fitted — with no outlet at all, pressure should climb to the machine's set point immediately. If it doesn't, that's a pump or OPV fault.
• The gauge climbs but the pump makes a strained, screeching noise.
• Pressure was always fine and has suddenly dropped with no change to your coffee or grinder.

7. When to Stop and Call a Technician

The casing of the machine is the boundary. Anything you can reach from outside it is fair game. The moment the problem is inside, stop.

Espresso machines combine mains electricity, pressurised hot water, and — on many models — a boiler operating well above 100 °C. These are not appliances to open speculatively.

Knowing what isn't wrong is genuinely useful information. When you call a technician and can say "it's not the gasket, I've replaced it; it's not scale, I descaled it last month; the pressure won't build even on a blind basket" — you've saved them diagnostic time and saved yourself money.

8. Your Maintenance Schedule

Almost everything in this guide is preventable. The faults our workshop sees most often are the ones that build up slowly in machines that were never cleaned properly — and by the time they're a fault, they're a repair bill rather than a five-minute job.

9. Frequently Asked Questions

Getting Help

Most of what looks like a broken espresso machine is a blocked one. Backflush it, descale it, check the gasket — and a machine that seemed dead often comes back to life.

When it doesn't, come to us. Di Pacci has supplied, serviced and roasted for Australia's coffee community since 2010. We run an in-house service workshop, stock genuine parts, and provide servicing across all five states we operate in. Tell us the symptom and what you've already ruled out, and we'll take it from there.