Collection: Boilers

Boilers for capsule coffee machines

Capsule machines use compact, fast-heating boilers (thermoblock or aluminium boiler). Limescale is the main enemy: it accumulates on the internal heating element, reducing thermal efficiency to the point of complete blockage.

Boilers for espresso and superautomatic coffee machines

Espresso and superautomatic machines have larger capacity boilers (often dual boiler: one for espresso, one for steam). In De'Longhi models, the steam and coffee boilers are separate components with distinct codes.

Boilers for electric moka pots

In De'Longhi Alicia electric moka pots, the boiler is the lower aluminium body that heats the water. It comes in versions for 2, 4, and 6 cups — not interchangeable with each other — and some versions include a reducer funnel for single servings.

Boilers for steam irons and steam generators

In steam generators (Polti Vaporella, Rowenta Perfect Steam, Braun CareStyle, De'Longhi Stirella), the boiler is the pressurised tank with an integrated heating element that produces steam. It is the component most susceptible to limescale and the most expensive to replace: regular descaling is essential to prolong its life.

Boilers for steam mops and Vaporetto vacuum cleaners

In Polti Vaporetto and steam mops, the boiler is a metal container that pressurises the water, smaller than that of steam generators but subject to the same limescale and wear issues of the heating element.

How a domestic boiler works

The boiler of a small appliance is a metal container (aluminium or stainless steel) with an integrated heating element that heats the water. When the water reaches the operating temperature (between 90°C for coffee and 130°C+ for pressurised steam), a thermostat regulates the on/off cycle. In steam generators and professional irons, there is also a safety valve that activates in case of overpressure. In dual boiler models (semi-professional coffee machines), the two boilers operate independently: one maintains the water for espresso at ~92–95°C, while the other produces steam at a higher temperature for cappuccino.

Maintenance and prevention of limescale

Limescale is the main cause of failure in domestic boilers. The accumulation of mineral deposits reduces the heat exchange surface, forces the heating element to operate at higher temperatures, and accelerates degradation. Some practical tips:

• Using filtered or low hardness water significantly reduces deposits
• Regularly follow the descaling cycles indicated by the manufacturer (generally every 200–300 cycles or every 2–3 months)
• In Polti Vaporella generators, use 50% demineralised water with tap water: completely demineralised water is corrosive to aluminium
• Avoid frequently emptying and refilling the boiler when cold: repeated thermal shocks stress the internal seals
• If the machine remains unused for weeks, completely empty the boiler to avoid hard-to-remove dry deposits

Most common problems and solutions

FAQ — Frequently asked questions