How to descale a Gaggia Classic

What you need

Use a descaler made for espresso machines. Vinegar is not recommended: it is less effective, it can leave a taste and it may affect seals. Our guide on descaling with vinegar explains the reasons.

• Gaggia descaler, or a descaler the manual approves for the Classic.
• A jug or container of at least 1 litre.
• A blind basket (a basket with no holes) for backflushing, if you plan to backflush.
• Espresso machine cleaning powder for the backflush.
• A screwdriver for the shower screen screw.

Descaling the boiler and solenoid

Running solution through the group head also clears the solenoid valve, which can stick when scaled. If water only dribbles from the group, scale may already be blocking it; our guide to a Gaggia Classic not pumping water covers that.

1. 1

   Remove any water filter from the tank, then mix descaler and water in the tank as the pack or manual directs.

2. 2

   Switch on with the portafilter removed and let the machine heat until the ready light shows.

3. 3

   Place a container under the group and press the brew switch to run about a cup of solution through.

4. 4

   Switch on steam briefly or open the steam knob with the brew switch on, and run some solution through the wand into a jug.

5. 5

   Switch off and let the solution sit for the time on the pack, often around 20 minutes.

6. 6

   Repeat, alternating group and wand, until the tank is nearly empty. Do not let the tank run dry.

7. 7

   Rinse the tank, fill it with fresh water and run it all through the group and wand in the same way.

8. 8

   Repeat the rinse with a second tank if any taste of descaler remains.

Note:The boiler, group head and steam wand get very hot and the wand releases steam under pressure. Keep hands clear of the outlets, never run the pump with an empty tank, and switch off and unplug before touching the group or removing the shower screen.

Backflushing the group

The Classic's three-way solenoid valve allows backflushing, which pushes water back through the group and out of the solenoid into the drip tray. It clears coffee oils from the shower screen and valve. Check the manual for your model's guidance, as advice on how often to backflush with detergent varies.

Fit the blind basket, add a small amount of espresso machine cleaning powder, lock in the portafilter and run the brew switch for about 10 seconds, then off for 10 seconds. Repeat several times. Remove the portafilter, rinse, then repeat with plain water to flush away any detergent.

Cleaning the shower screen and gasket

Let the machine cool fully and unplug it. Undo the central screw under the group head and remove the shower screen and the plate behind it. Soak them in hot water with a little cleaning powder, scrub with a brush and rinse. Wipe the inside of the group, then refit the screen and tighten the screw firmly but not hard.

While the screen is off, check the rubber group gasket. If it feels hard, is cracked or water leaks around the portafilter, replace it. Gaskets are standard parts for the Classic family.

How often to do each job

Your water hardness decides how often to descale; our hard water guide explains how to check it. To compare the Classic with other Gaggia models, see our Gaggia range guide.

Gaggia machines compared →

Frequently asked questions

How do I clean a Gaggia Classic Pro? Rinse and purge daily, backflush regularly, clean the shower screen every few weeks and descale on a schedule set by your water hardness.

Can I backflush the Gaggia Classic? Yes, its three-way solenoid valve allows it. Follow the manual's guidance on detergent use.

Why is my Classic slow after descaling? Loosened scale can lodge in the solenoid or shower screen. Clean the screen and run more fresh water through. If it persists, a repairer can clear the solenoid.

Does the Classic E24 descale the same way? The principle is the same. Check the E24 manual for any model-specific steps.