Microgen’s Stirling unit is basically maintenance free. People usually only report to us in case of problems. We hear only little about all those thousands of units which are running in the field… Therefore, we were more than pleased to unexpectedly run into the following: a webpage from the Kothe family from Marl in Germany. Their unit, installed in 2012, had already made over 46.000 operating hours!

This January however, we heard that the unit had shut down shortly after. Something which of course came as a disappointment for us, but also something we wanted to understand.

After a brief investigation it became clear that the cause was a non-MEC stirling related problem: flue gas condensate dripping back from the heat exchanger into the burner. This was related to the construction of the early Remeha units.  After replacing the ceramic collar and thermocouple the unit is back up and running, no longer with the Kothe family but at the Microgen Center in Doetinchem, the Netherlands. An endurant and lasting machine as it is, we are keeping tight track of its behaviour. The 50.000 hours milestone is almost in sight! The Remeha unit at the Kothe family has a new stirling engine installed and with some finetuning of the burner it is also running smoothly again.