Feature●Installation: The de-icer should be placed at the northwest corner of the pond, up against the liner. In large or deep ponds, place unit in the shallowest part of the pond, preferably near a bank. The unit will turn on automatically when the temperature around the heating element is at 35-￢F and turns off when the water temperature is at 45-￢F (at -10-￢F air temperature).●Air Test: Perform an "Air Test" to determine whether the de-icer is heating properly and the thermostat is functioning properly.●Place the unplugged de-icer into the freezer for 30 to 45 minutes to activate the thermostat.●Remove the de-icer from the freezer and quickly plug the de-icer into a working outlet.●The unit will heat up and then shut off, indicated by a slight clicking sound. The clicking sound means the thermostat is working properly.Description Large, low-profile pond de-icer resists tipping against blustery winter winds. The unique design of the Pond Saucer minimizes heat loss due to frigid winds for reliable performance. Maintains a vent hole in the ice to ensure proper gas exchange throughout the winter. Thermostatically-controlled de-icer operates only when necessary for reliable energy-efficient performance Gª( turns on automatically at 35-￢F and turns off when the water temperature is at 45-￢F. Made from easy-to-clean, weather resistant thermoplastic material. 200 watts. 12-1/2" diameter and only 1-3/4" high. 10 ft power cord.