The small valve that lets the boiler breathe
When the machine heats up, the boiler is initially full of air. It has to get out before the steam pressure rises – otherwise the machine works against an air cushion and the pressure on the gauge does not match what arrives at the steam tap. When it cools down, the opposite happens: the steam condenses, the volume collapses and a vacuum forms in the boiler. This valve handles both directions without anyone having to press anything.
This version has a 1/4 inch thread and carries the part number L190; the documentation also lists the number C219900560 next to it. This sets it apart from the two 1/8 inch vacuum valves on the steam tap, which both carry the number L192.03.
When it needs replacing
During heat-up, the valve hisses constantly instead of only at the start. It drips during operation. Steam pressure builds up more slowly than usual. After switching off, the machine audibly draws in air or water is sucked back. Or the valve is scaled and stuck in one position – then it either no longer closes at all or no longer opens at all.
At a glance
| Type |
Vacuum valve, mechanical |
| Location |
On the boiler or in the steam line, at a 1/4 inch connection |
| Fits |
The documentation does not name a machine for this item. Send us the serial number and we will check the fit. |
| Included |
One vacuum valve. Seals are not mentioned. |
| Part number |
L190, listed in the documentation together with C219900560 |
| Version |
1/4 inch thread. Material and overall length are not documented to us. |
| Installation |
Installation by a specialist recommended |
| Brand |
La Marzocco |
Important for installation
The valve sits on a pressurised part of the machine. Work is only carried out on a machine that is switched off, cooled down and depressurised. A vacuum valve is never readjusted, closed off, bypassed or blocked – not even if it hisses for longer than you would like. Anyone who silences an audible valve takes away the boiler's pressure equalisation. We deliberately do not give step-by-step instructions here.
Vacuum valves in the catalogue
The valves differ in thread and version, not in name. These are the items we carry:
According to our documentation, the older vacuum valve L193.02 for GS3 and Linea Mini with water drain is no longer available; that is why we do not carry it.
Who it is for
For workshops that always replace the vacuum valve during an overhaul instead of descaling it, and for anyone looking for exactly this valve with the number L190 from a service document.
What goes with it
Related parts include the two vacuum valves on the steam tap, the rod and the Teflon insert. More valves can be found in the Original spare parts section, the rest of the range under La Marzocco accessories and spare parts. If you have the boiler open anyway, it is worth taking a look at Machine and grinder cleaning.
From our workshop
In Bern and Zurich, we listen carefully during heat-up: a vacuum valve hisses briefly at start-up and then stops. If it keeps hissing, we make a note of it instead of pressing it shut – a valve that no longer closes costs heat-up time and electricity every day. That is our routine, not a manufacturer requirement. What is in the cup in the meantime: Nutty Delight, Cozy Chocolate or Very Nutty. More under Coffee beans.
No returns
Original spare parts are excluded from exchange and return. They are sourced specifically for each order and cannot be resold after installation or a trial fitting on the machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a line and we will check the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
Is this a solenoid valve?
No. The vacuum valve works purely mechanically via pressure and spring force. It has no coil, no connection and no electrics.
How does it differ from the L192.03 vacuum valves?
In the thread and the location: this item has 1/4 inch, the two L192.03 have 1/8 inch and sit on the steam tap. Both are linked above.
Can I save a scaled valve?
Sometimes descaling removes the scale, but often the seat still leaks afterwards. We replace the valve during an overhaul instead of betting on it.
Can I close the valve if it hisses?
No. A vacuum valve is never readjusted, closed off, bypassed or blocked. If it hisses constantly, it needs replacing.
Can I see the part in your shop?
Yes. We are happy to show it to you in our showroom in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b.
Questions about fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
