After we stared at the wiring connected to the hamann pump we invited someone with secret hamann voodoo skills to have a look at it.
After some troubleshooting he found the problem. The sensor in the black water tank wasn’t giving a ‘tank full’ signal.
It turned out that it wasn’t wired correctly. Perhaps it never was?! We wonder if the previous owner ever had the hamann working in automatic mode.
After several days with the Hamann operational we confirmed that the float sensor gives the required signals:
- Tank getting full, time for Hamann to start.
- Tank level low, time for Hamann to take a break.
- Tank full
That last one is important in order to avoid overflowing the black water tank. We found out by forgetting to put the Hamann in the automatic mode such that it didn’t start when the sensor gave the signal. On the bright side we can confirm that the related alarm signal is loud and clear 🙂