The ring that seals the steam valve spindle
The spindle of a steam valve turns every time someone froths milk – in a café, that means hundreds of times a day. This O-ring sits between the moving spindle and the valve body and stops steam from escaping at the knob. The manufacturer lists it under part number H.1.005.
No other sealing point on an espresso machine sees so much movement at such high temperatures. It is normal for the ring to tire after a while, and it is part of planned maintenance – not in the category “defect”, but in the category “wear”.
When it’s due
Steam or moisture escapes at the knob even though the valve is closed. The knob becomes stiff and feels gritty or, conversely, turns too easily and has developed play. A white limescale rim appears under the cover. When removed, the ring is hard, flattened in two places and occasionally torn. Escaping steam is not a cosmetic problem – the spot should be fixed promptly.
At a glance
| Type |
O-ring for the steam valve spindle |
| Dimensions |
Not stated in our documentation – the part number is what counts |
| Material |
Not stated in our documentation |
| Location |
Between valve spindle and valve body |
| Fits |
La Marzocco machines that list number H.1.005 at this position |
| Scope of delivery |
1 O-ring – without spindle, without spring, without valve |
| Part number |
H.1.005 |
| Version |
Original spare part |
| Brand |
La Marzocco |
| Installation |
Installation by a qualified technician recommended |
Important for installation
The steam valve is connected directly to the steam boiler. Let the machine cool down, disconnect it from the mains and fully release the pressure before opening anything – escaping steam scalds instantly and without warning. We deliberately do not provide step-by-step instructions here. After reassembly, the valve is opened and closed several times under pressure and the spot is checked.
Who it’s for
For service companies overhauling a steam valve spindle, and for hospitality businesses that deliberately keep this ring in stock. In a business that uses a lot of milk, it is a part you are more likely to need twice a year than twice a decade.
What goes with it
We stock the matching spindles individually: the Steam valve spindle Linea PB and the Steam valve spindle KB90. Complete valves are available as Complete steam valve GS3 and Steam valve Linea Mini R. You’ll find an overview in the Original spare parts section and under La Marzocco accessories and spare parts.
From our workshop in Bern and Zurich
When a steam knob gets stiff, many people reach for pliers first. We do it the other way round: take the valve apart, remove the limescale from the spindle and seat, fit new seals – after that, the knob turns easily on its own again. Force is almost always the wrong approach here. This is our routine, not a manufacturer’s specification. We then do the milk test with Nutty Delight, sweeter with Cozy Chocolate, stronger with Very Nutty. More under Coffee beans.
No returns
Original spare parts are excluded from exchange and return. They are procured specifically for each order and cannot be resold once they have been installed or test-fitted on a machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a quick line and we’ll clarify the fit together. Your rights in the event of defective goods remain unaffected.
Which machine does this ring fit?
Our documentation doesn’t name a model for H.1.005, only the installation point. That’s why the product has no model tag. Send us the serial number and we’ll check the fit before you order.
Are the spindle or spring included?
No, you only receive the O-ring. We stock spindles and springs as separate items.
Is one ring enough, or do I need several?
That depends on the valve type. Many valves have two rings on the spindle – check your exploded view to see how often H.1.005 appears there.
My knob is dripping despite a new ring. What now?
Then the valve seat is usually calcified or the spindle is worn. Both can only be assessed with the valve disassembled – get in touch and we’ll take a look.
Can I pick up the part at your showroom?
Yes. We’re in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Let us know shortly beforehand and the part will be ready for you.
Questions about the fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
