Fabdec have been at the forefront of unvented water heating since the 1980’s and have now pioneered an exciting revolution with the EXCELSIOR i, a true internal expansion cylinder based on an internal air gap utilizing 3S patented technology, the ‘Self-Sustaining System’.

The internal air gap device offers many improvements to unvented water heating installations such as a compact solution by negating the need for an external expansion vessel taking up valuable room and reducing installation time.

In addition any unvented system over a period of time the expansion vessel will lose its charge and will have to be re-pressurized. An alternative to fitting an expansion vessel is to arrange for a volume of air to be provided above the water level inside the cylinder (internal expansion).

The issue with this arrangement is the air is absorbed by the water. A procedure then needs to be carried out to manually replenish the air in the vessel, resulting in regular maintenance. But the Fabdec 3S technology changes this philosophy by automatically re-charging the air gap in the vessel every time water is drawn off by the user. This means less inconvenience for the tenant and a reduced workload for the maintenance schedule over the product life cycle of 25+ years. Designed and manufactured in the UK it is without equal.