Technically, a geothermal probe is a bore hole of vari-ous depths in which a closed loop system is inserted, through which a medium flows and, due to its lower temperature, collects the heat from its surroundings (geothermal energy), is heated up and brings it to the heat pump. The probes are usually placed up to depth of 140 m. Probes are assembled from pipes , made from the PE 100 material.

A probe is made of four pipes, welded at the ends in a double U pipe. When inserting the probe into the bore hole, the spacers are installed at regular intervals, which ensure the pipes are evenly spread along the width of the borehole.

There is also a middle pipe which is intended for the final filling of the hole with liquid concrete; at the end after the probe has been inserted and has withstood a pressure test. Concrete filling improves the thermal conductivity and thus the effectiveness of the opera-tion of the probe as a heat exchanger.so.