Review on ISTA I H615 Inline External Heater by Haley Johnson

I really liked this external aquarium heater. It kept a fairly stable temperature in my 125 gallon tank. Yesterday I noticed that the tank was cold and the heater temp gauge read HI. So I turned it off and temporarily put in a couple of immersion heaters. Today I was hoping that a good cleaning would solve the problem, but it didn't. So I decided to open it. As you can see from the photos some water got in, the insulation around the heating element did not work well when wet. You can see burnt/melted plastic parts and corroded power connectors. The cause of the failure was an open circuit in one of the temperature sensors. This is designed to work right outside of a tank attached to a water hose. Of course there will be water outside the case, but that water has to stay outside. All they had to do was make the case waterproof, either with an O-ring around the case opening, or completely seal the case. You can get an electric shock with such a product. At best, they've saved a dollar, and that's why the product is dangerous. If you don't plan on using it in a dry environment (haha), think twice before you buy it.