"I’ve read that metallic heating elements go bad and ionize with repeated use and that ceramic or glass are the best/purest options. Do you inspect used/returned heating elements for degredation? "
Our glass and stainless steel cartridges are intended to be used and then recycled (rather than refilled) and when used in that manner the heating post/coil is not overheated so it should not degrade over the lifetime of the cartridge. Whenever we have any defective or returned items, we always inspect them to find the cause for failure, whether it be clogging, displaced wiring, lack of connectivity, or some other form of device failure.
drjulicrockett