The small brass part that keeps the GS3 steam valve in place
Between the steam valve and the boiler sits a brass flange that connects and seals the two. You never see it and never think about it – until it starts to drip or the thread no longer grips cleanly after many service cycles.
This version has a G1/4 male thread to an M20 female thread and a height of 31 millimetres. Part number F.4.007.02; it replaces the former F.4.007.01.
When it's due
Moisture or a white limescale ring appears at the joint with the steam valve, even though the seal is new.
The thread can no longer be tightened without play or shows visible damage from the last service.
The valve is no longer firmly seated, wobbles when you operate it or turns too easily.
At a glance
| Type |
Brass flange, connector |
| Location |
Between steam valve and boiler |
| Fits |
La Marzocco GS3 |
| Scope of delivery |
One flange, without seals |
| Part number |
F.4.007.02, replaces F.4.007.01 |
| Version |
G1/4 male thread to M20 female thread, height 31 mm |
| Installation |
Installation by a qualified technician recommended |
| Brand |
La Marzocco |
Important for installation
This part sits in a pressurised line. Before any work on it, the machine must be switched off, unplugged, cooled down and depressurised – a boiler is still under pressure hours after being switched off. We deliberately do not provide step-by-step instructions here.
When screwing it in, what counts is a clean sealing surface, not force. Overtightening distorts the thread and the seal seat, and after that it drips permanently. You're better off leaving this job to a qualified technician or bringing the machine to us.
Who it's for
For workshops and technically skilled GS3 owners working on the steam valve. The part is inexpensive, and if the valve is dismantled anyway, replacing it is almost always worthwhile.
If you're just looking for a leak, check the seals first. Only if they're new and it still stays damp is it the flange's turn.
Goes well with
From our workshop
At our workshops in Bern and Zurich, this part goes into the overhaul basket as soon as a steam valve is taken apart – it costs little and saves a second appointment if things still stay damp afterwards. Our workshop routine, not a manufacturer requirement. We do the function test afterwards with milk and then pull an espresso with Nutty Delight. You'll find our beans in our coffee bean range.
Returns excluded
Original spare parts are excluded from exchange and return. They are procured 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'll check the fit together. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
What's the difference from F.4.007.01?
F.4.007.02 is the current number and replaces the former F.4.007.01. If your documentation still shows the old number, this is the right part.
Are seals included?
No. Only the brass flange is supplied. Seals and O-rings are separate items.
Why is there no photo of this item?
We don't currently have a product image for this part. If you need one, write to us – we'll photograph it for you from our stock.
Does the flange also fit a GB5?
In our documentation it is assigned to the GS3. Send us the model and serial number and we'll check before you order.
Can I see and collect the part in Bern or Zurich?
Yes. We have two showrooms: Bern at Gerberngasse 44 and Zurich at Hagenholzstrasse 50b. Drop us a line beforehand, and we'll have the part ready and look at it together on your machine.
Not sure whether this is the right number? Write to us at [email protected] with the model, year of manufacture and serial number, and we'll check it for you. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
