# What's the boiler pressure on your ecm/profitec HX?



## kennyboy993 (Jan 23, 2017)

Thought it would be useful to collect some data on this. I've been tweaking and am interested if others have a significantly different setting.

It's a balance between cooling flush amount and recovery time - and depending on use, different pressures would be suitable.

On my Mechanika it currently tops out at about 1.35 so a range of around 1-2 to 1.35


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## El carajillo (Mar 16, 2013)

What does the manual recommend ?


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## kennyboy993 (Jan 23, 2017)

Explicitly? It doesn't

Implicitly - 1.25..... perhaps.


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## El carajillo (Mar 16, 2013)

I think you will find that is also the factory setting:good:


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## kennyboy993 (Jan 23, 2017)

If any ECM hx owners are interested:

After more experimentation, reading and chatting to BB - I've set my mechanika boiler pressure between 1 and 1.2 bar.

Best thing I ever did. Far from causing more sour shots - the temp reduction has made the cooling flush so much shorter it's so much easier to manage.

I was flushing too much at higher boiler temp - it's so easy to go over.

Flushing with a machine at this temp is so forgiving - you get a sense it was designed for this pressure.

And steaming is still absolutely fine, even for larger amount for e.g. Latte


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## espressotechno (Apr 11, 2011)

Normal steam pressure range on commercial HX machines is 1.0-1.2 bar.

If customer complains that the coffees are "too acidic", we will reduce the steam pressure to 1.0 bar (or even 0.9 bar) to obtain a sweeter brew.


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## kennyboy993 (Jan 23, 2017)

espressotechno said:


> Normal steam pressure range on commercial HX machines is 1.0-1.2 bar.
> 
> If customer complains that the coffees are "too acidic", we will reduce the steam pressure to 1.0 bar (or even 0.9 bar) to obtain a sweeter brew.


That's interesting - so you might lower the pressure to try and increase brew temperature?

Assuming lower temp increases acidity (what I've read and my own experience) then perhaps a lower pressure enables shorter cooling flush and actually a higher brew temp?

Unless I'm misreading this and the customer uses the word acidity where we might use bitterness or astringency.


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## espressotechno (Apr 11, 2011)

Lower steam pressure = lower boiler water temp. = lower HX temp = lower brew temp.


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## MalcolmH (Dec 10, 2016)

Hi @kennyboy993,

I have the same machine as yours and I d like to try reducing the boiler pressure a tad. Mine currently stabilises at around 1.4.

Is the adjustment made from the top of the machine, just in front of the water tank or underneath, also, in your experience what fraction of a turn will drop it by around 0.2

Thanks, Malcolm


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## kennyboy993 (Jan 23, 2017)

Hi Malcolm - it's adjusted on top.

I don't have sirai pstat I have the other one (can't remember it's name) I assume u have the same.

It's was about 45 degrees though can't be sure.

Key thing for me was to give it a good 30 mins to stabilise as the gauge pointer settles down a bit after an adjustment. So it's always been a little bit of trial and error - make adjustment, watch gauge, watch the gauge again after 30 mins and only then screw top back on if in desired range.


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## big dan (Apr 11, 2012)

Old thread but just to add my 2 cents.

I have an old rocket Giotto Evo 2 and got the coffee sesnsor thermometer and found that even with my large cooling flush temps from the sensor during brewing were above 95C.

I decided to lower my pressure stat and I was quite aggressive and turned it down to around 0.9 bar.

Made a huge difference as now group head still stays at an average of 95c when idle but the cooling flush pushes it up to 98 max and then drops quickly after that and can brew between 90 and 93 easily which is my preffered temperature generally. In the cup this took my shots from good to great with more sweetness and a rounder flavour.

Downside is steam pressure is lower but I actually like this as it gives me loads of time to get the milk right. Probably went from around 15 seconds to 30 seconds to steam my milk. I also swapped steam tips for a smaller 2 hole one.

Think mine has a sirai pressure stat and found that you probably need to turn at least a quarter to a half to notice much of a change.


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