Review on Submersible Fish Tank Heater - 500W Digital Aquarium Heater with Readout for 60-100-150 Gallon Saltwater or Freshwater, External Thermostat Titanium Safe Controller, Includes 2 Artificial Plants as a Gift by Theresa White

The seller gave me a new heater and it works great 👍Here are the tips: #1. Let it sit in the aquarium for 2 hours, not 40 minutes, before turning on #2. You change the temperature by pressing the F/C button on the cable to the desired temperature. Old review - installed correctly and it doesn't stop. Flashing of E1. A heater shouldn't be that difficult to manage. I followed the instructions exactly. Also, the instructions are terrible. If you want to adjust the temperature, you just need to press the F or C button on the cord. He doesn't tell you! It says to tune from C to F by pressing this button. I still can't get E1 to stop blinking. Annoying 😠