Coffee machines DeLonghi are deservedly considered one of the most reliable in their class, but even high-quality equipment is subject to wear. The heart of any espresso machine is the water system, which provides the correct pressure and temperature for extraction. If you notice that the coffee is pouring out in a thin stream or the device is making an unusual noise when starting up, the problem most likely lies in the water supply unit.
Understanding the operating principle of this mechanism will allow you to independently diagnose most faults without calling a technician. In this article we will look in detail at what the hydraulic system consists of and how to properly maintain pump and what to do if formed scale inside the tubes.
Regularly checking the tightness of connections is the key to the long life of your device. Water is an aggressive environment, especially when heated, so rubber seals and plastic fittings lose their properties over time. Ignoring the first signs of a leak can lead to a short circuit in the electronics.
Design features of the hydraulic system
Water supply system for coffee machines DeLonghi is a complex chain of components connected in series. The main driving force here is the electromagnetic pump, which creates the required pressure of 9-15 bar. It is this parameter that is critical to obtaining the correct foam. cream on the surface of the espresso.
Water from the tank passes through a special filter cartridge, which softens hardness and traps large particles. The flow is then directed to the pump, from where it enters the thermoblock under pressure. The thermoblock is a key heating element through which water passes immediately before contact with the coffee tablet, instantly heating up to 90-95 degrees.
The entire system is connected by flexible silicone or Teflon tubes of different diameters. It is important to understand that the diameter of the tube affects the flow rate, and the material affects the durability of the connection. Plastic fittings are often color coded to indicate flow direction or connection type.
The secret to quick diagnosis
If, when you turn on the coffee machine, the pump hums, but no water comes out, most likely the system is airy or the valve is clogged. Try removing the supply tube in front of the pump and blowing it out to remove the air lock.
Some models are equipped with additional flow sensors that monitor the volume of fluid passing through. This allows the machine to automatically stop water flow when the cup reaches a preset volume. If this sensor fails, the machine may not add enough water or, conversely, overfill the cup.
Main malfunctions of the feed unit
The most common problem of coffee machine owners DeLonghi is a decrease in pump performance. Over time, limescale deposits on the inner walls of the pump and pipes, narrowing the flow area. This causes the machine to work longer and the quality of the coffee to deteriorate.
The second common problem is depressurization of connections. Rubber O-rings O-ring dry out from constant contact with hot water and temperature changes. As a result, puddles appear under the machine, and the pressure in the system drops, preventing the coffee tablet from breaking through.
⚠️ Attention: If you find water under the case, immediately unplug the device. Operating the coffee machine while wet may result in electric shock and burn out the control board.
There are also common problems with the check valve, which prevents water from flowing in the opposite direction. If the valve “sticks” in the open position, water may flow out of the cappuccino maker or group by gravity when the machine is turned off. This is not only wasteful, but also harmful to internal components.
A noisy pump is another symptom that should not be ignored. A loud knocking or humming noise may indicate worn pump bearings or solid particles getting into the impeller. In such cases, replacing the water supply unit becomes inevitable.
Diagnose pressure and flow problems
Before disassembling the device, it is necessary to carry out initial diagnostics. If the coffee flows too quickly and appears pale, the pressure in the system is not high enough. This may be caused by wear on the pump or leaking pressure through leaking connections.
If the liquid drips drop by drop or does not flow at all, but the pump hums, most likely the system is clogged. The blockage may be in the filter, in the thermoblock itself, or in the output group. To accurately determine the location of the blockage, a step-by-step inspection of each section of the highway will be required.
- 🔍 Check the water level in the tank and the position of the float - sometimes the magnet on the float moves and the machine “thinks” there is no water.
- 🔍 Inspect all visible connections for drips or wet spots.
- 🔍 Listen to the sound of the pump: a steady hum is normal, an intermittent knock is a sign of a malfunction.
- 🔍 Check if the silicone tubes inside the case are twisted after previous cleanings.
To measure pressure at home, you can use a pressure gauge connected instead of a portafilter, but this requires certain skills. A simpler way is to visually assess the jet: it should be powerful, but not splash, forming a dense “mouse tail” stream.
If diagnostics show that the problem is not scale or filters, you will have to move on to a more in-depth analysis of the components. Often the culprit is the solenoid valve itself, which simply stops opening upon command from the control board.
Step-by-step instructions for replacing the pump
Replacing a pump is a procedure that requires accuracy and adherence to a sequence of actions. First you need to remove the top cover of the case and the side panels to gain access to the insides. Do not forget to disconnect the device from the power supply before starting work.
Drain the remaining water from the system by disconnecting the tubes from the pump and thermoblock. Place a container as water may spill out under pressure. Carefully unscrew the mounting screws holding the pump and remove it from its seat.
☑️ Replacing the pump in a coffee machine
When installing a new pump, pay attention to the direction of rotation of the shaft and the location of the inlet/outlet holes. They must strictly correspond to the original. Connect the electrical connector, making sure the contact is secure.
After assembling all components, it is necessary to conduct a test run. Turn on the car and let it warm up. Run the water several times without coffee to remove air from the system and check for leaks. If everything is dry and pressed, the repair can be considered successful.
It is important to use original spare parts or high-quality analogues with identical performance characteristics. Installing a more powerful pump may result in ruptured tubes or damage to the thermoblock due to excess pressure.
Prevention and descaling
Regular decalcification is the only way to extend the life of the water supply unit. Hard water contains calcium and magnesium salts, which crystallize when heated and settle on the walls. This process is inevitable, but it can be controlled.
Use only special decalcifying products recommended by the manufacturer. Acidic solutions effectively dissolve lime deposits without damaging rubber seals and plastic parts. Citric acid or vinegar may be too harsh for some ingredients.
| Type of pollution | Symptoms | Elimination method | Frequency |
|---|---|---|---|
| Scale in the thermoblock | Noise when heating, long drainage | Chemical decalcification | Once every 2-3 months |
| Filter clogged | Poor water supply to the tank | Replacing the cartridge | Once every 2 months |
| Wear of seals | Leaks under the hull | Replacing O-rings | As it wears out |
| Air lock | Spitting water, intermittent flow | Bleeding the system | When changing water |
Remember to flush the water reservoir every time you change the fluid. A biofilm often forms on its walls - a slippery coating, which is an ideal environment for the proliferation of bacteria. Wash the tank with warm water and a mild detergent.
Use filtered or bottled water with low mineralization. This will significantly reduce the rate of scale formation and extend the intervals between machine maintenance.
If you live in a region with very hard water, it makes sense to install an external reverse osmosis filter on the faucet or use ready-made softener cartridges that are installed directly into the tank of the coffee machine.
Parts selection and compatibility
When searching for spare parts for DeLonghi It is important to consider the model of your device. Although many components are common, there are differences in tubing length, connector type, and pump dimensions. The most common brand pumps Ulka or Ceme.
Pay attention to the pump supply voltage. Most household models use 220-240 Volt pumps, but there are also low-voltage 24 Volt versions operating through a converter. Installing an unsuitable pump will cause it to burn out instantly.
When ordering O-rings, it is better to have an old sample or an exact drawing with dimensions with you. Even a millimeter difference in cross-sectional diameter can lead to a leaking connection under high pressure.
⚠️ Attention: Do not use petroleum-based silicone lubricants on rubber seals in contact with drinking water. This can lead to the appearance of foreign odors and tastes in the coffee, as well as destruction of the rubber.
Buy spare parts from trusted suppliers who can guarantee the origin of the goods. The market is filled with cheap copies, the lifespan of which is several times less than the original. Saving on a small part can result in costly repairs of the entire unit.
Water quality and regular maintenance determine 90% of the service life of a coffee machine. Ignoring prevention leads to replacing expensive components 3 times faster.
Questions and answers (FAQ)
Can I use the coffee machine if water is leaking from the tray?
No, operating a device with a leak is strictly prohibited. Water may enter electrical contacts, causing a short circuit or fire. It is necessary to find the source of the leak and eliminate it.
How often should you change your water softener filter?
The standard cartridge resource is about 50 liters or 2 months of use, depending on the hardness of the water. Some models have an indicator that will remind you when replacement is necessary.
Why does the machine not fill with water after replacing the pump?
Most likely, an air lock has formed in the system. Try removing the tube at the pump inlet, turning on the machine to let water flow, and quickly reconnecting the tube. Also check that the hoses are not pinched.
What is the danger of ignoring the noisy operation of the pump?
Noise indicates that the pump is overloaded or has mechanical wear. At any moment it can jam or burn out, leaving you without coffee. In addition, vibration can loosen other fasteners inside the case.