50, 100, and 150 watt Aqueon heaters have a thermal fuse inside them. If they overheat (such as running dry) the fuse burns out and the heater is dead. The light will come on but it will no longer heat. Sounds like this is what is happening here. Did you forget to unplug the heater during a water change anytime recently? That would do it.
I would suggest using an Aqueon Pro heater which is made of unbreakable plastic and aluminum and comes with a thermal switch (the switch will reset when the heater cools down after an overheat). Or you could just go back to the Aqueon glass heater and remember to unplug it before doing a water change.
Andy
I would suggest using an Aqueon Pro heater which is made of unbreakable plastic and aluminum and comes with a thermal switch (the switch will reset when the heater cools down after an overheat). Or you could just go back to the Aqueon glass heater and remember to unplug it before doing a water change.
Andy