Very low pressure water inlet/supply query

[steem21]

Hi all,

This is my first post in this forum! I've been using a Rancilio Silvia for the past two years and now have the opportunity to upgrade to a secondhand La Spaz Vivaldi II.

I think I've managed to source everything for a quick and easy plumb in from my cold water supply using John Guest fittings. My problem though is this: my cold water supply is from a large tank in the attic, which is 6m (20ft) above the machine and is at very low pressure (gravity fed really). To check this, I bought a water pressure gauge, put it on the cold water feed, and the dial barely flickered! So maybe not even 1 bar of pressure.
Also, I'm planning to feed the washing machine off the same feed, so I have a 15mm T joint with a 1/4" pipe to feed the La Spaz. I guess this arrangement of taking water from a 15mm pipe down to a 1/4" feed will still drop the pressure further? And I will also have a filter before the water hits the Vivaldi. The filter connections are 1/4" I think but I can try to get as much of the piping to be a larger diameter like 3/8" if this will make a difference.

My questions are:
Will the S1 rotary pump be ok will such a low inlet water pressure? Also will the 1/4" feed cause the pump to run dry? I know a solution will be fitting a pump to increase the water pressure but this will be too much for the wife! So not a solution really. Also I've seen the Flojet and bottle solution but space is tight already so no more kitchen space for that!

I've posed the question on Home-Barista and had some advice, but it really sounds like my options are limited.

I would be grateful for any advice from anyone who has had experience with plumbing in a S1 with very low inlet pressure.

Thanks

Steve

[JohnB]

A large tank in the attic? Rainwater? The machine will be happiest with 30psi/2 bar. The pump pressure is usually set to 9bar at 30psi over here so if you were running less then one bar l/p you might have some issues. You might be able to adjust the pump pressure to compensate but thats awfully low line pressure.

[steem21]

A large tank in the attic? Rainwater? The machine will be happiest with 30psi/2 bar. The pump pressure is usually set to 9bar at 30psi over here so if you were running less then one bar l/p you might have some issues. You might be able to adjust the pump pressure to compensate but thats awfully low line pressure.

Ha! Rainwater! I might get more pressure with a good rain shower. I stay in an old tenement flat which has mains water feeding a tank in the shared attic before fed to other flats. It's a bit antiquated but unfortunately that's what I'm working with. I guess the issues are of the pump running dry or cavitating?

[JohnB]

I doubt the 1/4" line will cause problems by itself as CC offers both 1/4 & 3/8 line/fittings for plumbing in the Vivaldi S1. That filter combined with the 1/4" line may cause problems with such low pressure. Can you source a 15mm to 3/8 fitting or better yet run a 15mm line into the filter & come out to the machine with 3/8?

[steem21]

I'm hoping to use as large a diameter of tubing as possible. I've sourced a JG 15mm equal T and I'll see if there's a filter that can take 3/8" or 15mm inlet and is not too restrictive on flow. So you're saying that, even if pressure is really low, as long as I don't restrict the rotary pump's intake by using larger pipes, I may be ok?

[PBL]

I am positive it not will feed the pump. I needs normal city water supply pressure, generally between 30 and 45 psi. I believe the 1/4 inch line would be adequate if the pressure was there. :( When I installed mine three months ago I had a temporary set up for the first day and the small ice machine line 3/16 inch or even smaller was not enough and the pump would not fill the boilers. Also I have heard that high pressure, say over 60 psi usually needs to be worked around.

[JohnB]

Must of us are using 3/16" line & running a pressure regulator set to 30 psi so you don't need a larger line or 45psi. Some guys on here have mentioned that they are running 20-25 psi with no problems. As long as the pressure isn't ridiculously low you can adjust the pump to get the 9 bar brew pressure. Remember you only need 2-3 oz of water to pull a double shot.

[JohnB]

So you're saying that, even if pressure is really low, as long as I don't restrict the rotary pump's intake by using larger pipes, I may be ok?

You are the beta tester on this one. Why don't you email the UK La Spaziale distributor or CC service & ask what they think.

[ronsil]

Also, I'm planning to feed the washing machine off the same feed, so I have a 15mm T joint with a 1/4" pipe to feed the La Spaz.

In my opinion if already your washing machine works OK off the gravity feed you should have no problem with the La Spaz. - I had an identical setup in an apartment where we used to live in Bournemouth. The cold water tank (with no pump) was in the flat, 12 feet above the washing machine, dishwasher and a plumbed-in Faema Coffee Machine. It worked OK just as long as everything was not being used at the same time.
Why not rig up the La Spaz by itself as a test before making any permanent plumbing arrangements?.

[steem21]

I had an identical setup in an apartment where we used to live in Bournemouth. The cold water tank (with no pump) was in the flat, 12 feet above the washing machine, dishwasher and a plumbed-in Faema Coffee Machine. It worked OK just as long as everything was not being used at the same time.
Why not rig up the La Spaz by itself as a test before making any permanent plumbing arrangements?.

Thanks Ronsil. This gives me hope that things may work out with the Spaz. I'm thinking of buying Eric's S1 VII but I don't want to find out that I have to start installing pumps in the kitchen because the feed to the Spaz is inadequate!

My other concern is that within an inline filter, the flow will be further reduced like JohnB suggests and the pump will start cavitating and struggling. I'm going to drop an email to Chris' Coffee to see what they say. I've already spoken to Steve at HB and the official line from La Spaz is a minimun of 1.5bar....however.....Dan Kehn at Home-Barista states that the rotary pump itself does not require a specific minimum inlet pressure but needs enough volume to feed the pump when it's on. So I'm thinking....3/8" inlet hose from the filter output to the machine and try not to turn on the washing machine whilst I'm brewing!

I'm wondering if my situation with the low direct-plumb inlet pressure is like how it is with the Izzo Alex. It's a pour-over/hand-fill machine with a rotary and the inlet pressure must be close to 0???

Thanks again for all your comments,

Steve

[ronsil]

- Hope it works out for you - interested in perhaps seeing pics when you are complete. Please don't hold me to it but I would be very surprised if you have a major problem. However I am known to be "good with coffee-bad with tools"

One final thing, you could not do better than buying Eric's Machine. Its a great deal he is offering from a well cared for home. Are you thinking of the complete deal or just the machine?. If the latter I could be interested in the bits & pieces.

[steem21]

Well everyone,

It's been a week with the VII plumbed into my extremely low pressure water system and I'm pleased to say that she's behaved very well. When I draw off lots of water from the water/steam boiler, the pump kicks in, I see 4bar pressure on the manometer, and the boiler fills without a hitch! I've even put in a inline carbon filter which resulted in a drop in flow (without filter, I filled a bucket with 4L in 1min and with filter, 3L in 1 min) but without any adverse effects on the pump. No cavitation either!

I'm absolutely delighted with this machine! However....I'm thinking of moving house soon....and I'm guessing this place will have proper plumbing so I might be faced with a new set of challenges soon!

Thanks everyone for their comments,

Steve

[JohnB]

What are you seeing for pressure when you pull a shot?

[steem21]

I see 9 bar of pressure on brewing a shot. Stuck the handheld pressure gauge and saw 9 bar too! The shots are excellent from this machine. What's great is that the consistency of quality shots is amazing!

[JohnB]

I see 9 bar of pressure on brewing a shot. Stuck the handheld pressure gauge and saw 9 bar too! The shots are excellent from this machine. What's great is that the consistency of quality shots is amazing!

Glad it worked out for you. It is a great little machine.