Hey I have the same heater and the same problem although Ive had no problem with it for 2 years. Did you just put in a new heater and it worked,cause I don't want to fry my fish.My heater isn’t working anymore and I don’t know why. I put my hand in to quickly move something around and felt that it was pretty cold. So I checked my thermometer and it shows 64 degrees Fahrenheit. I check to see if my heater is unplugged but it’s not. It’s a new heater than came with the tetra glofish tank set so I have no idea as to why it would stop working. The red light indicator that shows its working came on for like 2 seconds then went back off. I have guppies and they seem fine just at the top waiting for food since the cover’s off. I’m really scared though because my tank just finished cycling and I was ecstatic and now this happens. I’m not able to get a heater today but if I need to I can get one tomorrow. Any advice will be appreciated. Thank you. This is a picture of how the heater is placed.