La Pavoni Professional V2.3 Copper / Brass

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MrSilver

#1: Post by MrSilver »

Hi guys,
Recently I bought a La Pavoni Profressional (guessing version 2.3) in Copper & Brass.

What a beauty - I however have some issues... From cold I can fire it up and approx 10 mins later I can release the false pressure and end up with a ready to pull machine... If I keep it on for a while the pressure drops to approx 0.5 bar and I cannot seem to do anything else than cool it completely before restarting... I suppose that I should be able to pull continous shots with this machine.....

What am I doing wrong - or what can I do to fix this?

Looking forward to your wise insights :-)

LObin

#2: Post by LObin replying to MrSilver »

Hi,
Congrats!
I also owned a brass and (formerly) copper V2.3 Professional that I fully restored and upgraded.



It seems to me that you have a defective pstat.
Is 0.5 bar the maximum pressure you read on the boiler gauge?

Does the gauge sit at 0 on a cold boiler?

Did you descale the machine? I'm asking since scale in the pstat pipe could also be causing this issue.

About pulling multiple shots... Even though these classic machines can pull amazing shots, they present a bit of a challenge when it comes to pulling multiple shots. Even more so on a 2nd gen machine.

The reason is this: there are no design that keeps the group head from getting hotter and hotter, eventually, way beyond the espresso range. A commercial lever, because of it's higher mass and being a bigger heat sink, stabilises and reaches a temperature equilibrium that is within the proper espresso range. It's temperature will go slightly up during a pull and then slowly down after a pull.

This doesn't happen on a La Pavoni. After a pull, the group just keeps getting hotter and hotter. You'll then have to use a cooling trick (cold bath, cold towel, turning off the machine or going for a thermal modification of the group head) in order to get back to the proper group head temperature and pull another shot.

Gen2's were design to heat up faster by allowing steam from the boiler to enter the neck and eventually the top of the group when raising the lever. There are modifications that slow down this process or again you have to rely on one of the cooling tricks.

Knowing the group head temperature through a digital thermometer or a temp strip is a necessity from my experience.

Tons of resource and lengthy discussions on this subject!

Cheers!
LMWDP #592

MrSilver (original poster)

#3: Post by MrSilver (original poster) »

Hi LObin,

Thanks for your reply!

the pressure gauge rests at 0 cold (sometimes 0.4). When firing up the Pavoni it reaches (after releasing fake pressure) about 0.9 to 1.0 bar. I can then pull my shots, but leaving the machine turned on it overheats fairly quickly.... There seems to be very little scale inside the boiler, but have not checked the stat itself yet...

When I then switch. off the machine and try again a bit later - ie 45 minutes later (not completely cold) it will only heat un to around 0.5 - 0.6 bar and seems stuck at that level :-(

I have a infrared digital thermometer - would that be suitable to read the group head temperature?

Is above behaviour as designed on a v2.3 pre-milennium or?

Have a great F1 race this weekend in Montreal! :-)

LObin

#4: Post by LObin replying to MrSilver »

The behavior you're describing is abnormal.
They are simple machines, really... At first glance, it seems like your pstat is faulty.
This is the correct replacement part:
https://www.theespressoshop.co.uk/en/La ... -2239.aspx

If you haven't changed the piston and portafilter gaskets yet, might as well order some at the same time. I prefer the blue or orange silicone over the stock black rubber. PTFE lubricant is also needed:
https://www.theespressoshop.co.uk/en/Su ... -5061.aspx

An infrared thermometer will work although I personally prefer the workflow with something attached to the group head. This guy sells a nice thermometer with a gold metal bracket if ever...
https://www.ebay.it/itm/175249237427

He's also sells a thermal insulator gasket kit that helps manage the group temperature and keep it from overheating drastically after a shot.

*I stopped following the F1 after Jacques Villeneuve although I keep hearing that I'll get hooked again once I've watched "Drive to survive"... :)
LMWDP #592

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baldheadracing
Team HB

#5: Post by baldheadracing »

MrSilver wrote:... the pressure gauge rests at 0 cold (sometimes 0.4). When firing up the Pavoni it reaches (after releasing fake pressure) about 0.9 to 1.0 bar. I can then pull my shots, but leaving the machine turned on it overheats fairly quickly.... There seems to be very little scale inside the boiler, but have not checked the stat itself yet...

When I then switch. off the machine and try again a bit later - ie 45 minutes later (not completely cold) it will only heat un to around 0.5 - 0.6 bar and seems stuck at that level :-(

I have a infrared digital thermometer - would that be suitable to read the group head temperature?

Is above behaviour as designed on a v2.3 pre-milennium or?

Have a great F1 race this weekend in Montreal! :-)
It's not normal, as Jonathon stated - well, the over-heating of shots is normal :lol:.

For the infrared digital thermometer - put a little bit of tape (electrical, duct, masking, etc.) on the group and aim your thermometer at that. The shiny surface of the group confuses direct readings.

One thing for the gauge - a common issue is the gauge needle gets bashed around because people don't open the steam valve to release pressure after a session (otherwise the gauge would read negative pressure once it is cold - if it could. It can't so this applies a twisting force to the indicator needle. If the piston seals are in good condition then this would also show as the lever lifting by itself.) This first manifests itself as a gauge that never reads zero and always reads a little high. Here's a video from Stefano explaining how to fix that:
Eventually the indicator needle doesn't seat tightly against the little rod that turns the indicator needle - when that happens the gauge doesn't move when hot, only when the gauge is cold. A very, very, very little tweak to tighten the grip of the indicator needle on the rod will fix that.

Good luck!
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

LObin

#6: Post by LObin »

baldheadracing wrote:It's not normal, as Jonathon stated - well, the over-heating of shots is normal :lol:.

For the infrared digital thermometer - put a little bit of tape (electrical, duct, masking, etc.) on the group and aim your thermometer at that. The shiny surface of the group confuses direct readings.

One thing for the gauge - a common issue is the gauge needle gets bashed around because people don't open the steam valve to release pressure after a session (otherwise the gauge would read negative pressure once it is cold - if it could. It can't so this applies a twisting force to the indicator needle. If the piston seals are in good condition then this would also show as the lever lifting by itself.) This first manifests itself as a gauge that never reads zero and always reads a little high. Here's a video from Stefano explaining how to fix that:
video
Eventually the indicator needle doesn't seat tightly against the little rod that turns the indicator needle - when that happens the gauge doesn't move when hot, only when the gauge is cold. A very, very, very little tweak to tighten the grip of the indicator needle on the rod will fix that.

Good luck!
Well explained Craig!
LMWDP #592