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The rhythm depends on use
At one to three coffees a day, a service every twelve months is enough. At five or more — which is what a typical office machine sees — it is worth shortening that to ten months.
Descaling has its own, much shorter rhythm: every two to three months on hard water, regardless of the service schedule. The menu programme is perfectly sufficient if you run it regularly.
Rinsing the brew unit once a week is the most important of the three and the cheapest, because it is free. It prevents the single most common failure customers bring us.
What a service achieves
A service means replacing seals in every working assembly, lubricating moving parts, cleaning the water and milk circuits, and measuring brew pressure and temperature. In other words: restoring the parameters the machine left the factory with.
The economics are simple. A PLN 450 service once a year costs less than one PLN 380 pump replacement plus one PLN 350 thermoblock replacement — and those two failures are most often the result of skipped maintenance.
There is also a difference you can simply taste. A serviced machine brews at the correct temperature and pressure, and that shows in the crema and the flavour.