How to Troubleshoot Common Espresso Machine Problems (Step-by-Step Guide)

Last updated: December 12, 2025

Even good espresso machines occasionally misbehave: water stops flowing, shots taste weak or bitter, steam pressure drops, or warning lights start flashing for no obvious reason. The good news is that most common problems have clear, systematic causes that you can diagnose at home without being a technician.

This guide gives you a structured way to troubleshoot your machine. We focus on symptoms you can see, hear, and taste and walk through practical steps in order — from the simplest checks to deeper maintenance tasks such as descaling and cleaning internal parts.

Important Safety Notes Before You Start

Espresso machines combine electricity, heat, pressure, and water. Before opening anything or removing panels, keep these basic rules in mind:

• Always unplug the machine before any internal inspection.
• Let the boiler and group head cool down to avoid burns.
• Do not open pressurized components (boiler, valves) while hot.
• If you see smoke, smell burning, or suspect an electrical fault, stop and contact a professional service center.

If at any point you are unsure, it is better to stop and get professional help than to damage the machine or injure yourself.

How to Use This Troubleshooting Guide

The easiest way to diagnose issues is to start from the symptom. Below, you will find the most common problems grouped into sections:

• No water or very little water coming from the group head
• Weak, sour, or bitter espresso
• Low or no steam pressure
• Leaks around the portafilter, drip tray, or under the machine
• Unusual noises (pumps, grinding, vibration)
• Warning lights, error codes, or machines that do not heat

For each symptom, start with the simplest check and move step-by-step. Do not change three things at once — fix one variable, test again, then move to the next step.

1. No Water or Very Little Water From the Group Head

If you press the brew button and nothing comes out (or only a few drops), the problem is usually in one of three places: the water supply, the pump, or a blockage in the group head or filter basket.

Step 1: Check the Obvious Water Supply Issues

• Make sure the water tank is properly filled.
• Confirm the tank is seated correctly — some machines will not draw water if the tank is not fully engaged.
• Check for kinks in the intake hose (plumbed-in or semi-plumbed systems).

Step 2: Test the Pump Without Coffee

Remove the portafilter, place an empty cup under the group head, and start a shot:

• If water flows normally → the pump works, and the blockage is probably in the basket or portafilter.
• If very little or no water flows → there may be air in the system, a blockage, or a failing pump.

Step 3: Remove Airlocks and Flush the System

If the machine was recently moved, transported, or run dry, air can enter the system:

• Fill the water tank.
• Run the pump with no portafilter for 20–30 seconds.
• Repeat 2–3 times with short pauses to avoid overheating the pump.

If water flow improves gradually, you likely had an airlock. Once the stream becomes stable, test again with coffee.

Step 4: Check for Blocked Baskets and Shower Screens

Old coffee oils and fine particles can clog the metal holes in the filter basket and shower screen:

• Inspect the basket against a light source. If many holes look blocked, soak it in a solution of espresso cleaner and hot water, then scrub gently with a brush.
• Remove the shower screen (if your machine allows it) and clean both the screen and the area behind it.

Step 5: Consider Scale Buildup or a Failing Pump

If you live in a hard-water area and rarely descale, mineral deposits can restrict water flow:

• Run a full descaling cycle following the manufacturer’s instructions.
• If descaling does not restore flow and the pump sounds weak or irregular, a professional inspection may be needed.

2. Weak, Sour, or Bitter Espresso

When water flows correctly but the espresso tastes wrong, the issue is usually extraction-related, not mechanical. The machine is doing what you tell it to do — but the grind, dose, or temperature is pushing the shot in the wrong direction.

Weak or Watery Espresso

Typical symptoms:

• Shot runs very fast (under 20 seconds for a double).
• Crema is thin, pale, or disappears immediately.
• Taste is flat, hollow, or just like strong drip coffee.

What to adjust:

• Grind finer — this is usually the most effective fix.
• Increase the dose slightly within your basket’s recommended range.
• Ensure you are tamping evenly and firmly.
• Use fresh beans roasted within the last 2–4 weeks.

Sour, Sharp, or Under-Extracted Espresso

Sour shots usually mean under-extraction — water did not spend enough time in contact with the coffee:

• Grind finer and aim for a longer shot time (25–30 seconds for a typical double).
• Check that the brew temperature is not set too low (on machines with temperature control).
• Distribute the grounds more evenly to avoid channeling.

Bitter, Burnt, or Astringent Espresso

Bitter shots usually mean over-extraction or overheated water:

• Grind slightly coarser to reduce contact time.
• Stop the shot earlier instead of running it long and watery.
• Purging a few milliliters of water before brewing on single-boiler machines can help stabilize temperature.
• Ensure your machine is not left overheated in “brew ready” mode for very long periods.

3. Low or No Steam Pressure

Weak steam makes it almost impossible to create proper microfoam. If your wand hisses but barely moves the milk, or only spits water, the problem is usually related to boiler temperature, steam valve blockage, or scale.

Step 1: Confirm You Are in Steam Mode

• On single-boiler machines, you must switch from brew to steam mode and wait for the ready indicator.
• If you start steaming too early, the boiler may still be at brew temperature, not steam temperature.

Step 2: Purge Condensation From the Wand

Before putting the wand in milk, always:

• Open the steam valve for 2–3 seconds into an empty jug.
• Let the initial water and condensation escape until you see consistent dry steam.

Step 3: Inspect the Steam Tip for Blockages

Dried milk inside the steam tip quickly reduces steam power:

• Unscrew the steam tip (if your model allows it).
• Soak it in espresso cleaner or hot water and scrub the holes with a small brush or needle.
• Wipe the wand thoroughly after every use to prevent recurrence.

Step 4: Address Scale and Boiler Performance

If steam power has slowly declined over months, limescale may be restricting heat transfer or steam flow:

• Run a full descaling cycle following your manufacturer’s guidelines.
• If descaling does not help and the boiler never reaches steam temperature, a thermostat or heating element fault may require professional service.

4. Leaks Around the Portafilter, Drip Tray, or Under the Machine

Leaks are annoying but often easy to localize. The key is to identify whether water is escaping from the group head, internal hoses, or overflow systems.

Leak Around the Portafilter

• Check that you are locking the portafilter fully into position.
• Inspect the group gasket (rubber ring) for cracks, flattening, or coffee residue.
• Clean the group head and groove where the gasket sits.
• If the gasket looks worn, replace it — they are inexpensive, consumable parts.

Water in or Under the Drip Tray

A small amount of water in the drip tray is normal, especially after backflushing or three-way valve operation. However, excessive pooling can signal issues:

• Make sure the drip tray is correctly seated and not overflowing.
• Check the return tube or channel from the group head — blockages can redirect water.

Leaks Under the Machine

Water directly under the machine can indicate:

• A cracked or poorly attached internal hose.
• A loose connection at the pump or boiler.
• A damaged water tank or tank seal.

If water appears only when the pump runs, an internal hose or connection is suspect. If you are not confident opening the casing, stop and contact a service technician — internal leaks near electrical components are not worth guessing with.

5. Unusual Noises, Vibrations, and Pump Sounds

Espresso machines are not silent, but significant changes in sound often indicate a developing problem.

Very Loud Pump With Little or No Water Flow

• Check the water tank: is it empty, misaligned, or blocked at the outlet?
• Confirm that no airlock is present by running the pump with no portafilter attached.
• If the pump continues to buzz loudly with no water movement, it may be running dry or failing.

Rattling, Vibrations, or Metallic Noises

• Ensure the machine is on a stable, level surface.
• Check that all removable panels, drip trays, and water tanks are seated firmly.
• On vibration-pump machines, some noise is normal, but new rattling can suggest loose screws or internal components.

Grinding Noises From a Built-In Grinder

• Never run the grinder with foreign objects or stones in the beans — if you suspect this, stop immediately.
• Check the hopper and burr chamber for stuck beans or compacted coffee oils.
• On some machines, grinding with an empty hopper can sound harsher but is not harmful if brief.

6. Warning Lights, Error Codes, or No Heat

Modern machines often display warning icons or error codes instead of simply “not working.” These codes are model-specific, but the logic behind them is similar.

Step 1: Check the Manual for the Exact Code

Many people skip this, but the manual often lists:

• The meaning of each blinking pattern or icon.
• Whether it indicates a descaling requirement, empty tank, or technical fault.
• Whether you can reset it yourself or need service.

Step 2: Confirm Basic Conditions

• Water tank filled and correctly installed.
• Bean hopper (for super-automatic machines) not empty.
• Drip tray and grounds container correctly inserted.
• Machine has fully completed its warm-up cycle.

Step 3: Descaling and Reset Procedures

If a descaling or maintenance light is on:

• Perform the full descaling cycle as described by the manufacturer.
• Use the correct descaling agent (too strong or unsuitable chemicals can damage the boiler or seals).
• Only perform hidden “service menu” resets if the manual explicitly allows it — forced resets can hide real faults.

Step 4: No Heat or Lukewarm Water

If the machine powers on but never heats:

• Check that the main power switch and any dedicated “brew/steam” switches are set correctly.
• For machines with adjustable temperature, confirm that the setting is not at minimum.
• If the machine shows heating errors repeatedly, a failed thermostat, sensor, or heating element is likely — this requires professional repair.

7. When You Should Stop and Call a Professional

Home troubleshooting is useful, but there are clear limits. To avoid safety risks and prevent expensive damage, do not continue DIY repairs if:

• You see or smell burning plastic or wiring.
• The machine trips your circuit breaker repeatedly.
• There are persistent internal leaks near electrical components.
• Descaling and cleaning do not restore water flow or heat.
• Warning codes in the manual explicitly state “service required.”

A qualified technician can test electrical continuity, pressure systems, and electronics with the proper tools. In many cases, timely professional service extends the life of the machine and is cheaper than a replacement.

Final Thoughts: Systematic Troubleshooting Beats Guessing

Espresso machines seem complex, but most everyday problems fall into a few predictable categories: water supply, scale, blockages, temperature control, and wear of basic parts like gaskets and steam tips. If you approach issues symptom-by-symptom and change one variable at a time, you can solve a large share of problems yourself.

Combine regular cleaning, scheduled descaling, and a basic understanding of how water, pressure, and temperature interact, and your machine will stay stable, predictable, and far less likely to fail when you need your morning espresso the most.