I really don't think it's defective. When you look at the large number of people who report identical scenarios (including myself) where the heater has to be set lower, but it remains constant, it's just a simple calibration issue. Every heater I've owned has been this way, minus the titanium heater with an external controller. I almost guarantee that if you exchange it, you'll get the same results with a new one. There are some heaters that you can calibrate, as most all companies recognize that the internal thermostat is usually a few degrees off.
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