Thought for sure I had this Hydor 200w heater calibrated. NOT! Got up this am to a tank temp of 82.3, nothing major but the heater itself was set for 79. House temp was 72. I took it out completely! Cleaned the glass & digital thermometers and now my tank temp is 77.6.
I ordered/received a Ehiem Jäger Thermostat Heater 150w. See how this one works.