# Londinium Compressa with 3bar of domestic water pressure, will it work ok?



## pbsmith (Feb 17, 2021)

Hi,

Just measured my water pressure at the point where the machine will be plumbed in and it measures just over 3bar, (im guessing this may vary a bit during the day due to demand)

Is this going to be enough to get good consistant results from the machine?

I understand what and how the mains water pressure is used for the preinfusion on the Compressa as it has no internal pump and also that on the more expensive L24 the pi is pump driven and adjustable via the app from 1-6 bar. But is this initial pressure whether mains driven or pump driven just used for the preinfusion?

Dark roasts low pi pressure lighter roasts higher pi pressures, but can you use a lighter roast at 3 bar and just accept it's never going to be quite as good as if you used 5bar? or will it not pull at all or be undrinkable?

I think I'm correct in saying on the older Londinium machines (and many other lever machines I'm guessing) the pi was governed by the boiler pressure - so 1.3ish bar max?

So, if I have between 1 and 3bar to play with (adjustable inline pressure valve) then it's got to be better than nothing and better than the older machines?

Or will losing the 3-6 bar or higher pressure restrict its use too much and make the purchase a bit pointless (but no way can i afford the L24!!) ?

My current levels of geekness are quite low so i won't be experimenting with loads if different beans and settings for the time being. I will find one that i like and that i can make well and will probably stick with it for a while and just enjoy it.

Thanks in advance


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## 4085 (Nov 23, 2012)

@pbsmith To a luddite like me, I am trying to work out where you control the bar pressure for pre infusion. Are you suggesting that you increase or decrease the water pressure via an external valve, or is there a feature on the machine that lets you do it please?


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## The Systemic Kid (Nov 23, 2012)

First Londiniums with vibe pump were set, as I recall, to 1.5 bar. With the Compress, the max line input pressure is set to 3 bar. If your line pressure is above that, you would need to reduce it. 1 - 3 bar is great for medium to dark roasts and 3 bar is probably fine for lighter roasts too.


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## DavecUK (Aug 6, 2013)

@pbsmith I think your getting yourself all confused and pulled out of shape, keep it simple, set up for 2 or 2.5 bar and go from there.


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## pbsmith (Feb 17, 2021)

dfk41 said:


> @pbsmith To a luddite like me, I am trying to work out where you control the bar pressure for pre infusion. Are you suggesting that you increase or decrease the water pressure via an external valve, or is there a feature on the machine that lets you do it please?


 As I understand it because the machine has no internal pump of it is on all the pressure for the pre-infusion comes from the pressure in the domestic mains water system this will be adjusted by a simple pressure valve from Screwfix fitted to the water feed into the machine. The boiler will also be filled by mains water pressure and the shot will be obviously be pulled with the pressure by the big spring as it is in all spring lever machines.


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## pbsmith (Feb 17, 2021)

The Systemic Kid said:


> First Londiniums with vibe pump were set, as I recall, to 1.5 bar. With the Compress, the max line input pressure is set to 3 bar. If your line pressure is above that, you would need to reduce it. 1 - 3 bar is great for medium to dark roasts and 3 bar is probably fine for lighter roasts too.


 The website says it goes up to 6 bar, But this extreme high-pressure is only really used for a very light Nordic roasts according to the stuff I found


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## pbsmith (Feb 17, 2021)

DavecUK said:


> @pbsmith I think your getting yourself all confused and pulled out of shape, keep it simple, set up for 2 or 2.5 bar and go from there.


 If you're saying the 3 bar I've got is fine for most applications then great I'll leave it at that and get my order in.
The pressure I have is clearly enough to fill the boiler and the mains pressure pressure is irrelevant for pulling the shot as that's done by the big spring I just didn't want the 3 bar I had to limit what coffee I could pre-infuse correctly and get a good shot from


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## DavecUK (Aug 6, 2013)

So you have not ordered it yet?


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## 4085 (Nov 23, 2012)

pbsmith said:


> As I understand it because the machine has no internal pump of it is on all the pressure for the pre-infusion comes from the pressure in the domestic mains water system this will be adjusted by a simple pressure valve from Screwfix fitted to the water feed into the machine. The boiler will also be filled by mains water pressure and the shot will be obviously be pulled with the pressure by the big spring as it is in all spring lever machines.


 So by that rationale, any machine set up to be connected to the mains as opposed to using a water reservoir could offer the same shot flexibility? I have had a few L1's mains connected and from experience, I can tell you that the maximum recommended level for an L1 is below 3 lbs line pressure. You are not advised to go above that using your in line regulator, but again, I cannot see how this can be quoted as a feature of the Compressa when the same rule applies or could apply to any machine


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## pbsmith (Feb 17, 2021)

DavecUK said:


> So you have not ordered it yet?


 Ordered it last Friday , just not paid for it yet. Had a chat with Reiss and he said it was ok to place the order to guarantee the price (5% rise anyday soon) Then pay after I got my water pressure tested. Plumber friend is away so I had to order a gauge from Amazon, it came today.


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## iroko (Nov 9, 2012)

pbsmith said:


> The website says it goes up to 6 bar, But this extreme high-pressure is only really used for a very light Nordic roasts according to the stuff I found


 The 6 bar is only for the LR24.


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## pbsmith (Feb 17, 2021)

iroko said:


> The 6 bar is only for the LR24.


 6bar is relevant for the Compressa

Cut and paste from the Compressa info page on Londinium.com

https://londiniumespresso.com/store/lever-espresso-machines/l1-compressa

"Please check the water pressure that you have available prior to purchasing this machine. You need 3 bar (45psi) for it to run properly, and up to 6 bar (90psi) for it to have the same light roast capabilities as the LR24"


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## DavecUK (Aug 6, 2013)

pbsmith said:


> "Please check the water pressure that you have available prior to purchasing this machine. You need 3 bar (45psi) for it to run properly, and up to 6 bar (90psi) for it to have the same light roast capabilities as the LR24"


 Really... so you need up to 6 bar for light roasts?


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## pbsmith (Feb 17, 2021)

DavecUK said:


> Really... so you need up to 6 bar for light roasts?


 following my chat with Reiss last week, he said to get the very best from an ultra light nordic roast, you should use the full 6bar of pre infusion. Not really relevant for me as up till then i had never heard of nordic roasts let alone wanted to brew with one.

No idea what levels of lighter roasts I'll be missing out on nailing if i can only manage 3 bar


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## 4085 (Nov 23, 2012)

@pbsmith I think you will find that is not totally correct matey.......in other blogs (and the advice given by Londinium seems to change every time they improve or change a product) that 2.5 lbs is the maximum advised line pressure......


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## 4085 (Nov 23, 2012)

pbsmith said:


> following my chat with Reiss last week, he said to get the very best from an ultra light nordic roast, you should use the full 6bar of pre infusion. Not really relevant for me as up till then i had never heard of nordic roasts let alone wanted to brew with one.
> 
> No idea what levels of lighter roasts I'll be missing out on nailing if i can only manage 3 bar


 So how exactly do you measure the difference using your machine, that adjustments to the line pressure seem to make?


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## DavecUK (Aug 6, 2013)

pbsmith said:


> following my chat with Reiss last week, he said to get the very best from an ultra light nordic roast, you should use the full 6bar of pre infusion. Not really relevant for me as up till then i had never heard of nordic roasts let alone wanted to brew with one.
> 
> No idea what levels of lighter roasts I'll be missing out on nailing if i can only manage 3 bar


 I suspect you won't be missing out on much, if anything...stop worrying and enjoy your machine. 🙂


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## Fez (Dec 31, 2018)

I have a londinium R(pre R24) with digital adjustable pre-infusion. I mostly enjoy medium roasts but occasionally venture into the lighter side(nothing Nordic). I set my pre-infusion a long time ago to 4bar and haven't changed it since. It came set from the factory at 3bar - I can't say that I notice a big difference between 3 and 4 bar on anything other than light roasts.

Personally if I were you, I'd skip worrying about what you might be missing out - feed it with 3bar and enjoy it


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## RobW (Dec 24, 2017)

Most of the time I leave my LR on 3 bar so I reckon you will be fine


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## pbsmith (Feb 17, 2021)

RobW said:


> Most of the time I leave my LR on 3 bar so I reckon you will be fine


 Fantastic, just what I wanted to hear

Thanks


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## cuprajake (Mar 30, 2020)

Just to quickly add to this.

The boiler set up on the l1 and compressa are different

Its true they can both be connected to the mains

The l1 uses it to fill the boiler only

The compressa uses it for pre infusion. Think of the water pressure as a pump in the case of the compressa. Its different as it has a pipe through the boilee which is what supplies the water, thats how it's heated. So varying the pressure input will change the shot. Also 6 bar max is the max working pressure of a main solenoid in there.


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