Review on Hygger Digital Temperature Controller Aquarium Heater - Shatterproof Titanium Tube, Submersible Fish Tank Heater for 60-180 Gallon Tanks, 500W 800W Power - Ideal for Saltwater and Freshwater by Amy Gregoire

The display stops working after a few hours without water. The temperature should show a few degrees higher than you would like to set correctly. Initially I was very excited and impressed by the two displays, but as I said, the water display stopped working. UPDATE : 12/10/2020 After the review was published, the seller contacted me and replaced the heater with a new one. So far the device is fine and the water indicator stays on. However, you need to set the temperature 5 degrees higher for it to be reflected in the tank. Overall I am very happy with the customer service and the heater itself. UPDATE 3/20/2021: The display constantly shows "Er” out of the water, the red indicator flashes while the heater is fully submerged in water. Super disappointed.