Soft copper that adapts once – and then seals
Copper washers work differently from rubber seals. When the fitting is tightened, the soft metal gives way and fills every irregularity in the two surfaces. That is exactly why they stay tight even where it gets hot and where an O-ring would have hardened long ago.
There is a downside: a copper washer adapts exactly once. If you loosen it and tighten it again, you are compressing metal that has already been deformed – and then wonder why the same spot gets damp again. That is why every fitting you open gets a new washer.
When it is due
- The fitting has been loosened – in that case a new washer always goes in.
- There is moisture, limescale traces or greenish deposits at the connection.
- The old washer is notched, cracked or unevenly flattened.
- The fitting only seals when you tighten it beyond the usual amount.
At a glance
| Type |
Copper washer, sealing washer for threaded fittings |
| Installation location |
Under a threaded fitting. Our documentation does not say which spot on which machine. |
| Fits |
La Marzocco. No model specified in our documentation – the number in your service documentation is what counts. |
| Contents |
One washer |
| Part number |
L4002 |
| Version |
Original spare part, copper |
| Brand |
La Marzocco |
| Installation |
Installation by a qualified professional recommended |
Important for installation
Copper washers almost always sit on fittings that carry pressure or hot water. Before opening, the machine is disconnected from the mains, the water supply is shut off, the pressure is released and everything is allowed to cool down. We deliberately do not publish step-by-step instructions for such places.
Who it is for
For service technicians and experienced DIY repairers who keep these washers in stock as consumables. If you open a fitting, it is better to have one on hand already – otherwise the repair takes one delivery time longer.
What goes with it
Other washers are the brass washer 14 x 7 x 0,5 mm and the copper washer for the GS3 pump and GB5 level probe. For venting on the brew group, there is the copper seal. More small parts can be found among the spare parts.
From our workshop in Bern and Zurich: We keep a small assortment of every copper size we use in the box, and we order them in multiples – nothing is more annoying than leaving a machine open overnight because of a twenty-centime washer. That is our routine, not a manufacturer requirement. Once the fitting is tight, the test shot follows, often with Nutty Delight or Cozy Chocolate, on long days with Very Nutty. More in our coffee beans.
Returns excluded
Spare parts are excluded from exchange and return. They are procured specifically for each order and cannot be resold after being installed or test-fitted on the machine. So check the model, year of manufacture and serial number of your machine before ordering – or drop us a quick line and we will clarify the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
Can I reuse the old copper washer?
We advise against it. Copper seals because it adapts to the surfaces the first time it is tightened. After that it is deformed and no longer gives way.
Where does this washer go?
That is not stated in our documentation. The binding reference is the number L4002 in your service documentation. Send us the serial number and we will check the fit in advance.
How many pieces are included?
One washer per position. If you are working on the machine anyway, it is best to order several at once.
Can I use an aluminium or brass washer instead?
No. Material and thickness are part of the sealing function. A different material behaves differently when tightened and does not seal as well at hot spots.
Can I look at the part at your shop?
Yes. At Gerberngasse 44 in Bern and Hagenholzstrasse 50b in Zurich, we are happy to compare the washer with the one you removed – bring it along.
Questions about fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
