The system extension is used when it is necessary to install the well at a depth greater than the standard height, or when due to other earthworks (e.g. land leveling, gardening work) the manhole is located below the ground level. It should be borne in mind to keep the minimum depth of the ground heat source (frost penetration zone) and the maximum depth of well foundation (for strength-related reasons).

Dedicated to manifold wells MINI, MEDI, MAXI extension with a height of 0.5 metre is available for heat pumps in the ground heat source system. This product is characterised by modular design so that it can be combined with other modules. They may be shortened to achieve the desired height of the manifold well (every 20 mm, a line is marked on the outer surface to facilitate cutting).