Abstract: The invention relates to a method for operating a fuel cell system (1), wherein, via a fuel line (20), hydrogen from a tank (21) and recirculated hydrogen from a recirculation circuit (50) as the anode gas are supplied to at least one fuel cell (101), and water (6) contained in the anode gas is removed by means of a water separator (2) integrated into the recirculation circuit (50), is collected in a container (3) and is removed from the system by intermittently opening a drain valve (41). The following steps are carried out to detect whether the container (3) is full: opening the drain valve (41) located on the container (3), detecting an erratic change in pressure in the fuel line (20) upstream of a hydrogen metering valve (51), identifying that the container (3) is empty. The invention further relates to a control device (27) for carrying out the method or individual method steps.

Abstract: Suggested is a procedure for operating a combustion engine (10), which comprises at least one pencil-type glow plug (12) that is assigned to at least one cylinder (11), and in whose exhaust gas area (13) at least one catalytic converter (14) is arranged, as well as a device for implementing the procedure. The pencil-type glow plug (12) is operated at least temporarily independent of the combustion engine operating status until reaching a preset measure for the conversion capability of the catalytic converter (14). The procedure according to the invention enables a low-emission operation of the combustion engine (10) simultaneously with minimal energy consumption and an extended lifetime of the pencil-type glow plug (12).