Planted Tank Enthusiast
Join Date: Oct 2004
Location: surf city, cali
update: i called marineland this morning, and per their usual good customer service they will be sending out a new heater. in this case, they are interested in receiving their old one to inspect. for future reference, the customer service number is as follows:
1-800-526-0650 - (Marineland Customer Service)
my suspicion (with the caveat that i have no idea how these things are manufactured) is that there are voids in the epoxy fill that when heated to high temperature cause expansion and cracking of the case. when further exposed to air, the can smoke and smolder like mine did. just a hunch...
its probably a great idea to either unplug or keep the heater completely submerged during water changes as you would any glass heater. i'm also willing to bet the lower power heaters (<100W) have less issues than the big ones.