The tightness of the gas valve can be sufficiently determined with a pressure of ± 100 to 150 mbar over a period of five minutes. Depending on the volume and any pressure deviation (e.g., minus 1 mbar) during this period, it is determined whether or to what extent the gas valve is leak-proof. If the temperature drops, the pressure decreases automatically; therefore, the user must ensure constant conditions regarding the ambient temperature. The ecom-DP-Profi-Set is designed for leak testing on gas valves as well as further pressure measurements on gas burners/gas heating systems.