My unica started to extract coffee too quickly even with finest coffee I can grind im getting a shot under 20s.
Grinder doesn't seems to have problems, in coffee machine i tried to replace pump and opv valve but result doesn't change.
Extraction is starting already around when pump pressure of 5bar and continues with same flow untill 12bar.
What can be the problem?

Hiya,

A few questions..

What basket size and dose are you using?
What is the brew pressure meant to be set at? 12 bars at max seems a bit excessive
How fresh are your beans and have you tried another type/varietal of bean?
What grinder are you using - finest grind is subjective. What grinder is it? Could you post a picture of your grind density? (add a banana for scale)

What changed before you started running into this issue?

Hi,
14g basket and I put about 18g of coffee, tried also over 20g but same result.
I have a breville smart grinder pro.
I tried with different coffee bean but no changes.
A pressure gauge to the group is showing over 10 bar (going over scale) is it normal, what should be the pressure to the group in E61 type?

manraz wrote:My unica started to extract coffee too quickly even with finest coffee I can grind im getting a shot under 20s.

Is this a new-to-you setup? If you search on channeling, you'll see the same top 3 possibilities: Coffee is stale, puck prep is off, or the grinder isn't up to the task.

manraz wrote:I have a breville smart grinder pro.

I've never used this grinder, but forum reports are mixed: breville smart grinder for espresso.

I been using this grinder last 5 years and never had any sort of problem, the finest coffee I was grinding used to stop the extraction, and I didn't change anything to my setup.
Also I tried with different coffee beans but same result.

If you can't grind fine enough to stop the extraction and the coffees you tried aren't abjectly stale, it's the grinder. After 5 years, the burrs could be worn out, or they could have been damaged by a stone. I'd start by replacing the burrs or considering an upgrade.