Review on BN-LINK Digital Temperature Controller - Efficient Heating Cooling Thermostat Controller for Reptiles, Aquariums, Homebrewing, and Fermentation by Erick Bowers

Apparently an electrical engineer wrote the manual. It's unnecessarily complicated and left me unsure if the poor performance was due to a defect or because I didn't have the right degree to run this thing. The idea is very simple, it has a heating candle and a cooling candle. Connect the heater for heating and the cooler for cooling. Then set the desired temperature followed by a value below the set temperature where you want to start heating and a value above where you want to cool down. But the manual is written in "PV < SV - HD" style, which is unnecessarily complicated for me. At the end I was wondering if I really understood what they are saying here. PV, which I called the sensor reading (not what they call it), is basically the temperature that the thermometer's sensor reads. SV is the setpoint (or the temperature you are aiming for). HD is the heat differential, which I believe means the number of degrees below SV that the hot plug is intended to operate at, and CD is the temperature differential, ie the number of degrees above SV that the point is intended to cool. Neither heating nor cooling was ever turned on. The PV value simply exceeds the SV value and generates an alarm. Then I manually turned off the heater and the temp fell within the set range, I turned the heater back on and then the temp dropped below the HD and I never turned on the heater plug. Because I only used heat in this application. , I could coolly ignore it, but I installed it anyway. And no matter what difference I set between hot and cold, the heating never came on, and neither did the cold. There is also no way to permanently disable the alarm. So I went nuts and squeaked the whole time trying to get this thing to work. You can deactivate the alarm with the CLR button, but only until the next temperature violation. Returned it and bought something else, hopefully more functional, clearer and less esoteric in the instructions for use.