Problem: My coffee maker is leaking water

Water leakage is a problem (not necessarily a fault, as we will see below) that mainly affects coffee machines with a high-pressure water circuit, such as espresso and capsule coffee machines. Due to their technology and extraction methods, other coffee machines such as drip coffee machines, Italian coffee machines and french presses hardly suffer from these water leaks.

So if you have an espresso machine, especially if you have had it for years, you have probably encountered this type of problem at some point, one of the most common in these machines. Fortunately, water leakage is easy to spot and therefore easy to fix.

When does a coffee machine lose water?

When this happens to your coffee maker, it is usually not due to a single, specific cause: many factors can influence whether a coffee maker loses water. This article will collect the most common ones and provide practical solutions.

To solve the issue, we will first locate the area where the water is leaking, either from the bottom or the top of the coffee maker. Once we have identified the problem area, we will study each component of the coffee machine located in that area to establish the cause and possible solutions.

Interestingly, many users have the exact opposite problem; as we can see in the article entitled my Dolce Gusto, coffee maker does not pour water. Anyway, let’s get to the point: if your coffee maker is leaking, read on because you will probably find the explanation and the solution in the following lines. We will distinguish between three main groups of cases in which a coffee maker loses water.

My coffee machine loses water underneath

This issue is common in portafilter espresso machines, but it can also occur in coffee capsule machines. It happens when you start the coffee machine and notice that water is leaking from the bottom. A small – or not so small – accumulation of water will form on your worktop.

If your coffee maker leaks water from underneath, it is probably due to a broken component or a poorly sealed gasket. To find out, first, disassemble the brewer and check which parts are susceptible to water leaks.

To disassemble the brewer, you need a cross or Torx head screwdriver for the rear and top panels. Of course, this depends on the particular model of the coffee machine. Also, remember that you should dismantle the coffee machine only if the warranty has expired. If your coffee machine still has a warranty, do not open it as this will invalidate it.

The most common elements that may leak are the water tank and the boiler or thermoblock (where the water passes through to heat it).

How to check the water tank

Remove the water reservoir and make sure that it is not broken anywhere and that the connections with the body of the coffee maker are in perfect condition. The most common problem is that the rubber gasket that seals the connection between the tank and the coffee maker has deteriorated over time.

water tank sealing gasket
Water tank sealing gasket

It may also be due to the tank valve not lifting correctly, so check that both the spring and the O-ring are in good condition.

Water tank valve
Water tank valve

How to check the heating element

On the boiler, problems usually come from the pipes that connect the heating element to the pipes. Water flows continuously through this point, and if the water pipe is damaged or deteriorates over time, it will leak out, leaving a dark stain on the boiler wall and dripping.

How can I tell if any of these elements are damaged? The best way to check for leaks or breakage is to run the machine with the outer casings removed. This way, you will detect any water leaks instantly. Here you have a practical example of a Cuisinart coffee machine leaking at the connection between the thermoblock and the water pipes:

What do I do if I have already detected the leaking element?

Well, most of the time, it will be a break or crack, so you will need to replace the damaged component with a new one. The easiest thing to do is to look online for the part you need, as there is more choice than physical shops.

If you are good at assembling and disassembling appliances and have the know-how to solder, you can repair the damaged parts yourself. In most cases, it is advisable to replace the whole component. In the long run, it is much more practical and economical.

Another possibility is that it’s only a hose or connection that has come loose, but no component is damaged. In this case, it is sufficient to return the free element to its original position manually. For example, the tube draining excess water in the drip tray or the water tank is not properly connected to the coffee machine. In both cases, the solution will be very simple.

My coffee machine leaks water through the coffee group

This issue is exclusive to espresso machines, of course. It occurs when water leaks out of the edges of the filter holder where we have added the ground coffee. This water will leak out in small amounts, little by little, and you will notice small drops sliding down the handle of the filter holder.

The cause of this water leakage usually lies in the gasket of the coffee group, which may be deteriorated or broken. This gasket is usually a black rubber gasket (also made of silicone) placed around the nozzle. Its function is to put as much pressure against the filter holder so that the space is hermetically sealed. You can see how to replace it in a Rancilio Classe 8 in the following video (It should be the same for any other brand and model):

Be aware that even if you change the gasket on the unit, you may still have water leaks in the filter holder. It can happen because the filter holder also wears out, either the basket or the filter holder structure itself. It is advisable to replace the entire filter holder when this happens.

Once the rubber gasket has been replaced, it is good to describe and clean the coffee group with a descaling product. Clogs often cause the water to go the wrong way or the seals to break prematurely. For example, in this video, we can see how a Delonghi coffee machine leaks from the bottom without being started even once:

My capsule coffee machine leaks water around the capsule

One problem with capsule coffee machines is that the water is not injected correctly through the capsule. When the process is done correctly, the water should flow directly from the coffee machine into the capsule, through the capsule under high pressure and out the bottom into your cup.

If there is a problem with the water injection system, water will flow out of the bottom of the capsule but also out of the sides and even over the top of the capsule holder. In short, the water will spill out and fall anywhere but into your cup. As an example, here you can see the consequence of this problem on a Dolce Gusto Circolo:

Main reasons for a capsule coffee machine to leak water

  • Firstly, the water nozzle may be clogged and not allow the water to flow normally. However, in some coffee machines, such as Nespresso machines (in their classic version), it is usually the disc behind the spout that is clogged. Whatever the capsule coffee machine, try using a needle to unclog the area where the water is injected.
  • Secondly, the capsule may be defective. It is common that water does not flow properly through the capsule if the capsule is refillable and poorly sealed. But it can also occur in original capsules when there is a manufacturing fault. In either case, the consequence is that the capsule is not hermetically sealed.
  • Thirdly, we may be placing the coffee capsules incorrectly in their compartment and, therefore, when the lever is lowered, our coffee machine does not pierce it properly. It is essential to be aware that the capsules must be in exactly the right position for the coffee to be extracted correctly. So, although it may seem obvious, check that the capsule is correctly positioned before starting the coffee machine.

The following video explains these problems in great detail for a Nespresso coffee machine:

As we explained in the previous step, it is always good to decalcify regardless of the problem and the solution we apply. It ensures that there are no obstacles or sediments in the water circuit.