Profitec Pro 600 grouphead pressure is 1 bar higher than OPV (brew) pressure

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ekkang1
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#1: Post by ekkang1 »

Hi folks,

I recently bought profitec pro 600 (dual boiler, vibe pump) with flow control. I set my opv(brew pressure) at 9 bar to extract 8-9 bar extraction. However, when I try to pull the shot with blind disc in, brew pressure is reading at 9 bar (at the machine), but group head pressure is reading at 10 bar which is 1 bar higher than opv(brew) pressure. It's happening same even when I pull actual espresso shot with proper grind size. Even with coffee puck, it is reading 10 bar at group gauge and 9 bar at brew pressure.

When I saw the lots of video from you tube, it shows that their machine (exactly same machine as mine) is reading same pressure from both group head and opv(brew pressure) gauge when they backflushing.
at (36:00)

I reached out to WLL where I bought it from, but they said it's normal and I asked why their demonstrated machine was reading at same pressure, then they never responded back to me.

Any thoughts? if mine and their (WLL) demonstrated machines are the same, aren't they supposed to be reading at same?

Thank you all!

mary133
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Joined: 2 months ago

#2: Post by mary133 »

Stop obsessing!

temperature, grind and coffee are FAR more important

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HB
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#3: Post by HB »

ekkang1 wrote:Even with coffee puck, it is reading 10 bar at group gauge and 9 bar at brew pressure... if mine and their (WLL) demonstrated machines are the same, aren't they supposed to be reading at same?
The onboard gauge is upstream of the gicleur in the grouphead and the brew gauge is downstream of the gicleur. Depending on the flow rate, they won't have the same reading, with the brew gauge having a lower reading.


From E61 Group Espresso Machine: Detailed Interior Schematics
mary133 wrote:...temperature, grind and coffee are FAR more important
Indeed! Especially considering that this model has flow control, the only pressure reading that matters is the one from the grouphead since it's measuring the actual brew chamber pressure.
Dan Kehn
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ekkang1 (original poster)
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#4: Post by ekkang1 (original poster) »

Thanks for your reply! So.. in my case... if I want to 9 bar extraction, then should I increase my brew pressure (opv) to 8 bar to get 9 bar reading from group head gauge? Thank you!

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HB
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#5: Post by HB »

Better yet, adjust the OPV to 12 bar and control the brew pressure exclusively with the flow control/grouphead gauge. Then you can experiment with a wide range of brew pressure profiles.
Dan Kehn

JRising
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#6: Post by JRising »

I agree with what Dan says directly above.



I have no trouble believing that your gauges are accurate enough, even if they are reading differently when there seems to be very slow flow.

Of course, if the head is reading higher when brewing against the blind filter, that's because there's nowhere for the water to go (Trapped between the check-valve and the blind-filter) and being heated by the element. Meanwhile the pump's gauge is being relieved over the OPV.