What Is Backflushing and Which Machines Can Do It?

Your manual says "backflush" and you don't know what it wants. Or a friend told you to do it and you're not sure your machine allows it. Start here.

What the word means

Backflushing means forcing water, or water with cleaner, back through the group head. One guide describes it as forcing water and cleaning solution back through the group head and three-way valve¹. A maker's manual says it removes stray coffee left in places that normal, day-to-day cleaning cannot reach².

You do it with a blind basket. That's a filter basket with no holes in it². With the holes blocked, the water has to go somewhere, and on the right machine it goes back through the group head.

Which machines can do it

This is the question that matters. One retailer's guide says only machines with a three-way solenoid valve can be backflushed¹. That valve is the part that lets the pressure out after a shot. Without it, the water has nowhere to go.

How do you find out whether yours has one?

1. Read the manual. Your manual is the quickest answer³. It will give backflush steps, or it will say not to.
2. Check what came in the box. A blind basket in the box is a strong hint, though it's not a guarantee³.
3. Check the group type. One retailer's guide says machines with an E61 group always have the valve³. That only helps if you know your group type, so the manual comes first.

Both the three-way valve and E61 points come from retailer guides, not from a maker³. Follow your own manual.

Machines that handle it a different way

Some machines don't backflush with a basket you fit yourself. One retailer's guide says superautomatic machines have their own cleaning cycles and shouldn't be backflushed¹.

Others use a disc or tablet plus a button on the machine. One maker's manual has a clear water back-flush that starts with the cleaning disc in the one-cup basket⁴. The aim, in that manual's words, is to remove residual coffee oils in the espresso water paths⁴. That is the maker's own method for its own machine. It isn't a step to copy onto other models.

Backflushing isn't descaling

They're two different jobs. One guide says backflushing and descaling are two different things¹. The same guide says backflushing removes coffee oils from the brew group and solenoid, while descaling removes mineral deposits from the boiler and water lines¹. For descaling, use the product and steps your maker names.

What to do next

• If your manual gives backflush steps, read Backflushing With a Blind Basket to see how to read them.
• If your manual says no, or says nothing, read Machines That Should Not Be Backflushed.

When in doubt, don't backflush. Follow your own manual.