The part that costs the least and annoys the most when it's missing
One franc forty. In this catalogue that won't even get you a screw head or a brass washer – but it does get you this FKM O-ring. And it is exactly the reason an espresso machine won't go into service on a Tuesday morning: because it has gone hard and the threaded fitting it sits in has been quietly leaking for days.
FKM, usually called Viton in the workshop, is a deliberate choice here. The material withstands higher temperatures than ordinary sealing rubber and stays stable against oils and greases. With a 2.62 mm cross-section, the ring belongs to the sturdier kind that can also bridge slightly larger gaps.
When it's due
A threaded fitting sweats, drips or builds up limescale even though it is tight. The removed ring is hard, discoloured or has a permanent flat spot. It breaks when you pull it off. Or you are servicing the machine and replacing seals on schedule instead of waiting for a failure – the most sensible option of all.
At a glance
| Type |
FKM O-ring, often referred to as Viton |
| Location |
Sealing point inside the machine; our documentation does not state the exact position |
| Fits |
Order by part number; our documentation does not name a specific model |
| Scope of delivery |
1 O-ring |
| Part number |
H.1.002 |
| Version |
Cross-section 2.62 mm, inner diameter 17.13 mm, FKM, hardness 70 ShA |
| Installation |
Installation by a qualified technician recommended |
| Brand |
La Marzocco |
Important for installation
The ring sits inside the machine at a pressurised point. Depressurise the machine, check the sealing surface, fit the ring, then check for leaks – in this order and without shortcuts. We don't give step-by-step instructions because we don't know the installation point. If you can't identify the threaded fitting with certainty, leave the job to a qualified technician.
Who it's for
For service companies and for anyone who reads H.1.002 in their documentation. At this price, a small stock is worth more than any deliberation: two or three in the drawer cost next to nothing and shorten a repair from days to minutes.
What goes with it
Also made of FKM is the O-ring 1.78 × 11.89 mm; for the hottest spot on the steam valve we carry the PTFE O-ring 2.62 × 12.37 mm. All seals are listed under Original spare parts, and the brand's full range under La Marzocco accessories and spare parts.
From our workshop in Bern and Zurich: As a rule, we order inexpensive parts in small quantities whenever a delivery is coming anyway. An O-ring costing a few francs that sits in the drawer for months is the cheapest insurance against a breakdown at the weekend. This is our own routine, not a manufacturer requirement. And because this kind of repair usually happens before opening time, we have the Very Nutty running alongside – strong enough for early hours. If you prefer something softer, take the Cozy Chocolate; everything else is in Coffee beans.
No returns
Original spare parts are excluded from exchange and return. They are sourced specifically for each order and cannot be resold once they have been installed or test-fitted on a machine. So before ordering, check your machine's model, year of manufacture and serial number – or drop us a quick message and we'll clarify the fit together. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
Is it worth ordering a single ring?
Most people order it together with other parts. Ordering it on its own works too – it's just that shipping then costs more than the ring.
Is FKM the same as Viton?
Viton is a brand name for this type of material. In the workshop, the two terms are used interchangeably.
Where does the ring sit in the machine?
Our documentation lists position H.1.002 without a location. We won't make one up. Write to us and tell us which drawing the number comes from.
Will an EPDM ring of the same size fit?
Mechanically yes, functionally not necessarily. If the manufacturer specifies FKM, stick with it.
Can I see the part at your place?
Yes. Come to our Showroom in Bern at Gerberngasse 44 or in Zurich at Hagenholzstrasse 50b. Bring the old ring with you and we'll measure it together.
Need several sizes at once? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
