When i first started vaping the Zenith ran it dry several times not paying attention to how low the e-liquid was and gotten nasty burnt taste then.
After a refill there was still a slight reminder of what i did, last time it happened i removed coil head and ran under warm water and then used the kitchen sink sprayer as well . I just shook the coilhead a bunch of times and then added some e-liquid with the hypo needle to its feed holes inserted and there was no foul taste.
Yours may or may not do the the same.
A rebuild able coil head OPTION would certainly be nice but after emailing Phil i was politely told that was not in the making.
Now i keep a eye on tank so it does not happen again but it may.