@Mical, thanks for the adventure. Regarding posts if it fails - empty sump and swap them out. Difficulty factor depends on size of and accessibility of your sump. What y don’t want is a heater that sticks to the sump like a reptile heater, those are tough to get off. I like the idea that it uses the sump as a heat sink of sorts and provides a nice even heat through the whole sump vs. 2 or more traditional heaters that don’t necessarily heat all the altering a sump chamber evenly. Could also use a traditional heater as backup to the WBH.