Coffee machine descaling and brew unit cleaning: step-by-step guide
Limescale and a dirty brew unit cause most breakdowns in automatic coffee machines. Regular maintenance takes 20 minutes and saves you a few hundred zł.
- Most common cause
- limescale, dried coffee in the brew unit
- Time
- 20–40 minutes
- Repair shop, if it doesn't help
- 140–340 zł for descaling and servicing
Use a descaler made for coffee machines. Vinegar and home-made mixes can damage seals and aluminium parts, and the manufacturer may refuse the warranty. Switch the machine off and let it cool down before taking out the brew unit.
Step by step
Run the descaling program
Almost every automatic coffee machine has a descaling program in its menu (for example “Descaling” or “Calc clean”). Pour in descaler mixed with water as the manufacturer instructs and follow the messages on the display. At the end the machine rinses the system by itself.
Take out and rinse the brew unit
In many machines (including Philips, Saeco, Siemens and Melitta) you remove the brew unit through a side door. Rinse it under lukewarm running water without any detergent and let it dry. De'Longhi units are usually removable too. In Jura machines the unit is built in permanently, so use the cleaning program with cleaning tablets instead.
Grease the unit's seals
Every few months, apply a thin layer of food-grade (silicone) grease to the unit's guides and seals. Without grease the unit runs stiffly and the machine shows errors.
Clean the drip tray, grounds container and nozzle
Empty and wash the drip tray and the grounds container. Clean the milk nozzle after every use, and take it apart and wash it once a week. Dried milk clogs the nozzle and spoils the taste.
Replace or install a water filter
A filter in the water tank greatly reduces limescale. Replace it every 2 months or when the machine tells you to, and set your water hardness in the menu (a hardness test strip is often included).
Switch coffee if the grinder keeps clogging
Very dark, oily beans leave a greasy residue in the grinder and the brew unit. Medium roast is much gentler on an automatic machine.
- The machine leaks underneath or from the inside.
- The pump runs loudly but no water comes out, even after descaling.
- The brew unit error doesn't go away after you clean and grease the unit.
- The machine doesn't heat the water or trips the fuses.
How much does a repair shop charge?
| Descaling and servicing at a repair shop | 140–340 zł |
| Brew unit repair / replacement | 200–610 zł |
| Pump replacement | 200–480 zł |
| Heating element or thermoblock replacement | 270–610 zł |
Typical prices at independent repair shops in Poland, October 2026. Authorised service centres and big cities can be more expensive.
Repair or buy new?
Automatic coffee machines costing 1500–4000 zł are almost always worth repairing. A repair shop usually charges a fraction of the price of a new one. The exceptions are the cheapest models and machines where limescale has destroyed several parts at once.
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How often should I descale my coffee machine?
With hard water, which is common in Poland, every 1–2 months, or less often with a filter. It's best to do it when the machine asks for it, and never ignore that message.
Can I descale with vinegar or citric acid?
Manufacturers don't recommend it. Vinegar damages seals, and citric acid in hot water can form deposits. A coffee machine descaler costs a dozen or so zł and is safe.
Why is my coffee lukewarm?
Most often it's limescale on the heating element or a cold cup. Descale the machine, warm up your cup and set a higher temperature in the menu. If that doesn't help, the heating element may be damaged.