I've been running two 200watt Aqua Medic Titanium Heaters for a long time now. I programmed one to kick on 0.1 degree before the other to reduce the on/off cycles of one heater.
I've heard stories of heaters failing and many people replace them annually before they fail. Mine have been working like champs for about 5 years now, I do have two spares ready for replacement when they do fail... touch wood!
