The Guru College

A Fool's Errand

Starting an adventure with an Astoria Argenta SAE-2/XL

After painstaking research, I have recently acquired a used commercial espresso machine. It’s a beauty. A retired machine that was in service for an estimated 10 years is now sitting in my office, challenging me to learn All The Things about the machine, restore it and…

For anyone who doesn’t have perspective on what this machine is, here’s it is, in all it’s glory:

A machine of this class has a certain set of challenges that you don’t find in ordinary home appliances. It’s 220v, and runs at a peak draw of 6325 watts - which means it needs a 30 amp circuit, but would be happier with 40 amps. It uses split-phase and doesn’t touch 110v at all, which makes no sense to most people who deal primarily in 110v applications. In North America, at the service entrance to the house, the current from the pole is broken up into 110v legs that are distributed about the house. The normal execptions to this are the electric clothes dryer and the electric stove. These use both 220v and 110v at the same time, which causes no end of headache for everyone. Even worse, until 1996, it was considered code to use the neutral conductor as a floating ground for these appliances. Modern code states that you will use a four conductor cable with three active lines and a dedicated ground. Because, you know, house fires.

Armed with this, the next step is getting water into the machine. It relies on line pressure to fill the boiler before the heating element is energized, so that has to be dealt with, and you need to wire the pump as well. The boiler itself is 15 liters. The local big-box retailer sells a number of hot water heaters smaller than that. They have limited application, but it stands that they exist as a product that sells in enough quantity to make shelf space a priority.

Further, to keep 4 gallons of water at 1.25 bar above atmospheric, for quick turnaround in a commercial environment, the machine has a 220v 6000W heating element. This may slightly outstrip a home user’s espresso needs by a factor of 60. Even on a busy day, I don’t pull 10 shots out of the La Pavoni, and this machine could easily pull 600 shots in a coffee shop during a work day. So I’m probably going to insulate the boiler to reduce the duty cycle, and I’ve started to look at ways to further reduce the load by adding telemetry to the mix.

I’ve been able to power the machine up to validate everything. Surprisingly, more worked than I expected. The pump is quiet, the sight glass is dirty but functional, both groupheads dispense hot water of correct proportion to the flowmeter settings (which means they are working correctly as well). Boiler auto-fill works, as does auto-cutoff. Anti-vacuum valve works. Steam arms work. Hot water dispenser works. Heating element works. Drains work, and the water comes out clean. Turns out the last user did drain the boiler when putting the machines away, which is good for me. There’s also no sediment, gunk or anything else visible in the water coming out, and it doesn’t have any odor.

I have spent the better part of 12 hours removing the old grouphead gaskets, which were carbonized, and after a replacement, I’ve been able to pull reasonable quality espresso from both heads. I still need to crack the boiler seal and visually inspect the scale buildup, but this machine has all the seriously expensive parts in working order.

I guess the next steps are to decide where to actually install it and then call a plumber to help work out water and drain lines, and an electrician to put the right socket in the right place.

Speaking At SurgeCon 2016 | Home