Glass is a good thermal conductor (better than plastic). One can also visually inspect the inside with a glass housing. The presence of water inside the glass housing gives an early warning to a bad heater. Sure, the heater could work for another 2 to 3 years, but why take this risk for a $25 item?
The original EJ LZ line is probably the best heater made to date. The newer TZ line adds adjustable temperature knob, which could lead to premature leakage. I suspect the bi-metallic sensor assembly is also cheaper, resulting in unstable temperature control.
Hagen has a new line of electronic heaters...Fluval Tronics. It's probably the same as the original Hagen Tronics, with minor tweaks.
The original EJ LZ line is probably the best heater made to date. The newer TZ line adds adjustable temperature knob, which could lead to premature leakage. I suspect the bi-metallic sensor assembly is also cheaper, resulting in unstable temperature control.
Hagen has a new line of electronic heaters...Fluval Tronics. It's probably the same as the original Hagen Tronics, with minor tweaks.
