HI,

I am a new Barista. I bought a new Expobar Brewtus IV a month ago. The machine was good and made great espresso. Yesterday, I adjusted the suction pipe inside the tank and let some air went inside the machine. I noticed that the pressure gauge indicated a wrong reading ( at 8 bar) at idle position. It seems that air was trap inside the machine. The pressure dropped to 2 bar when started brewing and went up to 8 bar maximum.
How to release the air inside the machine?

Regards

KM HO

fm255611 wrote:The pressure dropped to 2 bar when started brewing and went up to 8 bar maximum.

That's all that matters. The pressure reading when the machine is idle isn't important.

To elaborate, pulling a shot introduces cooler water into a closed system, but then you suddenly close off the main exit at the end of the extraction. As the water in the boiler warms up, it expands and the pressure rises. The reading on the espresso machine's internal gauge when idle will vary depending on where its tee is located and what check valves/bleeder valves/solenoids are on the same pathway, but again, the pressure reading when the machine is idle isn't important.