Developed in the KLOVER workshops to increase thermal yield and safety, this revolutionary system uses the principle of “bain-marie“ by providing a home heating system fitted with a closed expansion chamber, while the “SICURO TOP“ product has a built-in open chamber and works, therefore, at zero pressure. With this system there are no more dangers due to increased pressure if the water reaches boiling point. The pressure inside the boiler unit is zero. An overflow pipe ensures safety in the event of boiling by discharging excess water from the upper tank, while water may be topped up via an automatic or manual device, depending on the type of model.