Quick answer

A leak at the joint between the top and bottom of your Alessi moka-163634">moka-163633">moka pot almost always means the rubber gasket has hardened, cracked, or lost its seal. Check the gasket first, then the fill level and how tightly you screw the two halves together. If the gasket is worn, replace it rather than buying a new pot.

Where the leak starts: gasket, threads, or fill level

Water escaping from the seam between the boiler and the collector is the most common complaint, and it is usually a sealing problem rather than a broken pot. The rubber gasket sits inside the top half and presses against the rim of the basket when you screw the pot together. Over time, heat and coffee oils make it stiff, so it stops filling the gap. A leak that appears only once the pot is on the heat, or that drips down the side of the boiler, fits this pattern.

Before you assume the worst, check how you are filling the pot. Water should sit just below the safety valve, not above it. If the boiler is overfilled, water can be forced up through the threads. Also check that you are not overtightening: screwing the halves together with excessive force can distort the gasket and make the leak worse, not better.

How to test the gasket without tools

Take the top half off and lift out the gasket with your fingertips. A healthy gasket is flexible and springs back when you pinch it. A worn one feels hard, looks shiny or flattened, or has visible cracks. If it has any of those signs, no amount of tightening will stop the leak. Reassemble the pot dry and check whether the gasket sits flat in its groove. If it will not stay seated, it has lost its shape and needs replacing.

When the fix is a replacement part, not a new pot

Alessi moka pots are designed to be serviced, so a leaking gasket is a repair job rather than a reason to replace the whole pot. The correct part depends on your model and size, so match the gasket to the pot you own before ordering. For example, the rubber washer set for the https://alessitye.com/products/la-cupola-163619La Cupola coffee maker in the 3-cup size is supplied as a pack of five and is not sold individually. That pack fits the La Cupola 3-cup, Pina 3-cup, and ARS09 3-cup models listed in the catalogue. If your pot is a different model, check the product page for the matching gasket.

One practical note: if your pot uses a whistle instead of a standard lid, that whistle is also available as a spare. The 3909/FIS purple basketball player whistle is a single replacement piece for traditional stovetop kettles and functions as the boil alert. It is a different part from the gasket, so do not order it expecting to fix a seam leak.

Leak diagnosis: symptom, cause, action, and when to stop

  • Water drips from the seam while brewing: The gasket has hardened or cracked and no longer seals against the basket rim. Remove the gasket and check for stiffness or cracks. If the gasket is stiff or cracked, replace it. If it is still soft, check the fill level and how tightly you screw the pot together.
  • Leak appears only when the pot is overfilled: Water above the safety valve can be forced through the threads. Fill to just below the valve and try again. If the leak stops with correct filling, no part is needed. If it continues, move on to the gasket.
  • Pot still leaks after a new gasket: Check that the gasket is the correct size for your model and that it sits flat in the groove. A mismatched gasket will not seal. If the correct gasket still leaks, stop and inspect the pot body for damage. At that point, replacing the pot may be the better option than further part orders.

Parts that solve common Alessi moka pot leaks

  • 200594: Rubber washer for coffee maker La Cupola, 3 cup size (A9095/3), Pina, 3 cup size (PL01/3), ARS09, 3 cup size (ARS09/3) - 5 pieces (not available for individual purchase). A five-piece pack covers multiple gasket changes, so you can keep a spare on hand rather than ordering again the next time the seal hardens. Check your model and cup size before ordering, because the pack is not sold as single washers.
  • 3909/FIS: This spare part, model 3909/FIS, is a purple basketball player whistle designed for use with traditional stovetop kettles. It adds a playful touch to your kitchen while serving as a functional replacement component. Purple basketball player design for a distinctive look. Compatible with traditional stovetop kettles. Functions as a whistle for alerting when water boils. Single spare part piece. If the leak is actually a failed whistle or you want to restore the boil alert on a compatible kettle, this is the correct single replacement piece. It is not a gasket, so it will not fix a leak at the seam.
  • 5076: The pepper castor has been in the Alessi catalogue since 1978 and belongs to the historical production. Ettore Sottsass conceived this pepper castor that has become a classic, a true archetype of restaurant industry and private service, an essential object, with its proportions, lightness and function. A reminder that Alessi designs for long service life. The same logic applies to moka pot parts: repair the item you own instead of replacing it when a small component wears out.