To obtain a good espresso coffee, we must make hot water pass through the ground coffee at a certain pressure, normally 9 bars. And if the water does not reach the minimum necessary pressure, the coffee will be similar to those obtained with a drip coffee maker; it will only be an infused coffee.
So if your Dolce Gusto coffee maker cannot inject the hot water with adequate pressure into the coffee capsule, the preparations will have more acidity and less body.
Lack of cleaning and maintenance as a cause of pressure failure
The lack of cleaning and maintenance is the main reason for any coffee machine breakdown, regardless of model or brand. Although from the number of inquiries I receive, it seems to be especially detrimental in Dolce Gusto coffee makers.
Periodic descaling is part of the proper maintenance that should be performed on the coffee maker. When not performing descaling, the machine can become clogged with limescale build-up on the internal parts. A clogged coffee maker does not allow water to pass through properly; the pressure will drop and cause other malfunctions.
Assuming that you have already checked that the injector is free of impurities and that this is not the problem, the next thing to do in case of a pressure problem in the machine is to descale it immediately.
To perform the descaling process, you can use the products recommended by Dolce Gusto or simply white vinegar. And although the manufacturers do not recommend to descale with vinegar, we have already explained in this other article why it can and should be used.
Defective parts as a cause of pressure failure
When we talk about broken components in the coffee maker, we are dealing with a more serious issue that will require disassembling the Dolce Gusto and replacing the part.
The defective internal components that can lead to a loss of pressure are the same as those described above, plus some others that will be mentioned in this section:
- Water pump
- Pipes & injector
- Control board
- Water tank gasket & flowmeter
The thermoblock is an element made of a metal alloy, inside which there is a very thin channel through which the water circulates. If there is an internal deformation, breakage, or rust, the water will not circulate with sufficient speed, resulting in a pressure drop.
Although these are extreme cases, they cannot be ruled out. To verify that the thermoblock is in good condition, we must disassemble the coffee maker and observe the physical condition of the thermoblock.
Defective water pump
The main cause for a Dolce Gusto coffee machine pump to stop working is, as we said before, the accumulation of limescale. However, it can also be damaged for other reasons, whether electrical or mechanical.
To check its good condition, we must disassemble the coffee maker and physically observe the pump. Many problems can be recognized through rust or burnt areas. As a last resort, you can disassemble the pump to ensure that there are no broken components inside.
Defective pipes or the injector
Both the pipes and the injector can become clogged due to causes other than limescale, and this clogging will lower the pressure with which the Dolce Gusto serves coffee. They can become clogged with coffee grounds, milk, or other substances.
In addition to clogging, the pipes and injector may bend or extrude, making the normal flow of water impossible. To check this, disassemble those parts that allow a visual inspection of these components.
Related: Dolce Gusto stuck capsule holder.
Damaged control board
If I have checked each of the components of the coffee maker, and I see that everything is correct, I change the control card for one from another machine in good condition. In most cases, the problem was in the control board.
It seems unbelievable that the control board could have a bearing on the pressure of the Dolce Gusto, but it does. The control board is responsible for the electromagnetism of the water pump, and when the signal sent is incorrect, the pump does not work properly, producing pressure losses.
To solve this, you must exchange the control card for a new one or a second-hand one.
Problem with the water tank gasket or the flowmeter
Sometimes, the pressure loss problem occurs at the other end of the circuit before even reaching the water pump.
When the pressure delivered by the Dolce Gusto will be low when the rubber gasket under the water tank, the water tank valve, or the flow meter is not working properly. For the pump to deliver water properly, it must be fed with water correctly.
Look for a defect in these components, and you will have the problem of lack of pressure in your Dolce Gusto coffee maker.